diff --git a/activesupport/lib/active_support/core_ext/date/calculations.rb b/activesupport/lib/active_support/core_ext/date/calculations.rb
index f0f67765c6..2212e0b3ca 100644
--- a/activesupport/lib/active_support/core_ext/date/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date/calculations.rb
@@ -7,24 +7,6 @@ require 'active_support/core_ext/time/zones'
 class Date
   DAYS_INTO_WEEK = { :monday => 0, :tuesday => 1, :wednesday => 2, :thursday => 3, :friday => 4, :saturday => 5, :sunday => 6 }
 
-  if RUBY_VERSION < '1.9'
-    undef :>>
-
-    # Backported from 1.9. The one in 1.8 leads to incorrect next_month and
-    # friends for dates where the calendar reform is involved. It additionally
-    # prevents an infinite loop fixed in r27013.
-    def >>(n)
-      y, m = (year * 12 + (mon - 1) + n).divmod(12)
-      m,   = (m + 1)                    .divmod(1)
-      d = mday
-      until jd2 = self.class.valid_civil?(y, m, d, start)
-        d -= 1
-        raise ArgumentError, 'invalid date' unless d > 0
-      end
-      self + (jd2 - jd)
-    end
-  end
-
   class << self
     # Returns a new Date representing the date 1 day ago (i.e. yesterday's date).
     def yesterday
diff --git a/activesupport/lib/active_support/core_ext/date/conversions.rb b/activesupport/lib/active_support/core_ext/date/conversions.rb
index 338104fd05..3262c254f7 100644
--- a/activesupport/lib/active_support/core_ext/date/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/date/conversions.rb
@@ -63,12 +63,6 @@ class Date
   alias_method :default_inspect, :inspect
   alias_method :inspect, :readable_inspect
 
-  # A method to keep Time, Date and DateTime instances interchangeable on conversions.
-  # In this case, it simply returns +self+.
-  def to_date
-    self
-  end if RUBY_VERSION < '1.9'
-
   # Converts a Date instance to a Time, where the time is set to the beginning of the day.
   # The timezone can be either :local or :utc (default :local).
   #
@@ -83,23 +77,6 @@ class Date
     ::Time.send("#{form}_time", year, month, day)
   end
 
-  # Converts a Date instance to a DateTime, where the time is set to the beginning of the day
-  # and UTC offset is set to 0.
-  #
-  # ==== Examples
-  #   date = Date.new(2007, 11, 10)  # => Sat, 10 Nov 2007
-  #
-  #   date.to_datetime               # => Sat, 10 Nov 2007 00:00:00 0000
-  def to_datetime
-    ::DateTime.civil(year, month, day, 0, 0, 0, 0)
-  end if RUBY_VERSION < '1.9'
-
-  def iso8601
-    strftime('%F')
-  end if RUBY_VERSION < '1.9'
-
-  alias_method :rfc3339, :iso8601 if RUBY_VERSION < '1.9'
-
   def xmlschema
     to_time_in_current_zone.xmlschema
   end
diff --git a/activesupport/lib/active_support/core_ext/date_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
index 48cf1a435d..1a3cf66a1b 100644
--- a/activesupport/lib/active_support/core_ext/date_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
@@ -1,5 +1,3 @@
-require 'rational' unless RUBY_VERSION >= '1.9.2'
-
 class DateTime
   class << self
     # DateTimes aren't aware of DST rules, so use a consistent non-DST offset when creating a DateTime with an offset in the local zone
diff --git a/activesupport/lib/active_support/core_ext/date_time/conversions.rb b/activesupport/lib/active_support/core_ext/date_time/conversions.rb
index ca899c714c..851012e3bf 100644
--- a/activesupport/lib/active_support/core_ext/date_time/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/date_time/conversions.rb
@@ -66,7 +66,7 @@ class DateTime
   # Attempts to convert self to a Ruby Time object; returns self if out of range of Ruby Time class.
   # If self has an offset other than 0, self will just be returned unaltered, since there's no clean way to map it to a Time.
   def to_time
-    self.offset == 0 ? ::Time.utc_time(year, month, day, hour, min, sec, sec_fraction * (RUBY_VERSION < '1.9' ? 86400000000 : 1000000)) : self
+    self.offset == 0 ? ::Time.utc_time(year, month, day, hour, min, sec, sec_fraction * 1000000) : self
   end
 
   # To be able to keep Times, Dates and DateTimes interchangeable on conversions.
diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb
index d9856f2e84..ccd0e9692d 100644
--- a/activesupport/lib/active_support/core_ext/enumerable.rb
+++ b/activesupport/lib/active_support/core_ext/enumerable.rb
@@ -1,41 +1,4 @@
-require 'active_support/ordered_hash'
-
 module Enumerable
-  # Ruby 1.8.7 introduces group_by, but the result isn't ordered. Override it.
-  remove_method(:group_by) if [].respond_to?(:group_by) && RUBY_VERSION < '1.9'
-
-  # Collect an enumerable into sets, grouped by the result of a block. Useful,
-  # for example, for grouping records by date.
-  #
-  # Example:
-  #
-  #   latest_transcripts.group_by(&:day).each do |day, transcripts|
-  #     p "#{day} -> #{transcripts.map(&:class).join(', ')}"
-  #   end
-  #   "2006-03-01 -> Transcript"
-  #   "2006-02-28 -> Transcript"
-  #   "2006-02-27 -> Transcript, Transcript"
-  #   "2006-02-26 -> Transcript, Transcript"
-  #   "2006-02-25 -> Transcript"
-  #   "2006-02-24 -> Transcript, Transcript"
-  #   "2006-02-23 -> Transcript"
-  def group_by
-    return to_enum :group_by unless block_given?
-    assoc = ActiveSupport::OrderedHash.new
-
-    each do |element|
-      key = yield(element)
-
-      if assoc.has_key?(key)
-        assoc[key] << element
-      else
-        assoc[key] = [element]
-      end
-    end
-
-    assoc
-  end unless [].respond_to?(:group_by)
-
   # Calculates a sum from the elements. Examples:
   #
   #  payments.sum { |p| p.price * p.tax_rate }
diff --git a/activesupport/lib/active_support/core_ext/exception.rb b/activesupport/lib/active_support/core_ext/exception.rb
index ef801e713d..ba7757ea07 100644
--- a/activesupport/lib/active_support/core_ext/exception.rb
+++ b/activesupport/lib/active_support/core_ext/exception.rb
@@ -1,3 +1,3 @@
 module ActiveSupport
-  FrozenObjectError = RUBY_VERSION < '1.9' ? TypeError : RuntimeError
+  FrozenObjectError = RuntimeError
 end
diff --git a/activesupport/lib/active_support/core_ext/module/introspection.rb b/activesupport/lib/active_support/core_ext/module/introspection.rb
index c08ad251dd..1893a9cfa6 100644
--- a/activesupport/lib/active_support/core_ext/module/introspection.rb
+++ b/activesupport/lib/active_support/core_ext/module/introspection.rb
@@ -57,27 +57,8 @@ class Module
     parents
   end
 
-  if RUBY_VERSION < '1.9'
-    # Returns the constants that have been defined locally by this object and
-    # not in an ancestor. This method is exact if running under Ruby 1.9. In
-    # previous versions it may miss some constants if their definition in some
-    # ancestor is identical to their definition in the receiver.
-    def local_constants
-      inherited = {}
-
-      ancestors.each do |anc|
-        next if anc == self
-        anc.constants.each { |const| inherited[const] = anc.const_get(const) }
-      end
-
-      constants.select do |const|
-        !inherited.key?(const) || inherited[const].object_id != const_get(const).object_id
-      end
-    end
-  else
-    def local_constants #:nodoc:
-      constants(false)
-    end
+  def local_constants #:nodoc:
+    constants(false)
   end
 
   # Returns the names of the constants defined locally rather than the
diff --git a/activesupport/lib/active_support/core_ext/object/instance_variables.rb b/activesupport/lib/active_support/core_ext/object/instance_variables.rb
index eda9694614..66caf9bec8 100644
--- a/activesupport/lib/active_support/core_ext/object/instance_variables.rb
+++ b/activesupport/lib/active_support/core_ext/object/instance_variables.rb
@@ -23,11 +23,7 @@ class Object
   #   end
   #
   #   C.new(0, 1).instance_variable_names # => ["@y", "@x"]
-  if RUBY_VERSION >= '1.9'
-    def instance_variable_names
-      instance_variables.map { |var| var.to_s }
-    end
-  else
-    alias_method :instance_variable_names, :instance_variables
+  def instance_variable_names
+    instance_variables.map { |var| var.to_s }
   end
 end
diff --git a/activesupport/lib/active_support/core_ext/range.rb b/activesupport/lib/active_support/core_ext/range.rb
index 2428a02242..c0736f3a44 100644
--- a/activesupport/lib/active_support/core_ext/range.rb
+++ b/activesupport/lib/active_support/core_ext/range.rb
@@ -2,4 +2,3 @@ require 'active_support/core_ext/range/blockless_step'
 require 'active_support/core_ext/range/conversions'
 require 'active_support/core_ext/range/include_range'
 require 'active_support/core_ext/range/overlaps'
-require 'active_support/core_ext/range/cover'
diff --git a/activesupport/lib/active_support/core_ext/range/cover.rb b/activesupport/lib/active_support/core_ext/range/cover.rb
deleted file mode 100644
index 3a182cddd2..0000000000
--- a/activesupport/lib/active_support/core_ext/range/cover.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-class Range
-  alias_method(:cover?, :include?) unless instance_methods.include?(:cover?)
-end
diff --git a/activesupport/lib/active_support/core_ext/string/encoding.rb b/activesupport/lib/active_support/core_ext/string/encoding.rb
index d4781bfe0c..236f72e933 100644
--- a/activesupport/lib/active_support/core_ext/string/encoding.rb
+++ b/activesupport/lib/active_support/core_ext/string/encoding.rb
@@ -1,11 +1,5 @@
 class String
-  if defined?(Encoding) && "".respond_to?(:encode)
-    def encoding_aware?
-      true
-    end
-  else
-    def encoding_aware?
-      false
-    end
+  def encoding_aware?
+    true
   end
 end
\ No newline at end of file
diff --git a/activesupport/lib/active_support/core_ext/string/multibyte.rb b/activesupport/lib/active_support/core_ext/string/multibyte.rb
index 400db2ce39..4e7824ad74 100644
--- a/activesupport/lib/active_support/core_ext/string/multibyte.rb
+++ b/activesupport/lib/active_support/core_ext/string/multibyte.rb
@@ -2,71 +2,55 @@
 require 'active_support/multibyte'
 
 class String
-  if RUBY_VERSION >= "1.9"
-    # == Multibyte proxy
-    #
-    # +mb_chars+ is a multibyte safe proxy for string methods.
-    #
-    # In Ruby 1.8 and older it creates and returns an instance of the ActiveSupport::Multibyte::Chars class which
-    # encapsulates the original string. A Unicode safe version of all the String methods are defined on this proxy
-    # class. If the proxy class doesn't respond to a certain method, it's forwarded to the encapsulated string.
-    #
-    #   name = 'Claus Müller'
-    #   name.reverse # => "rell??M sualC"
-    #   name.length  # => 13
-    #
-    #   name.mb_chars.reverse.to_s # => "rellüM sualC"
-    #   name.mb_chars.length       # => 12
-    #
-    # In Ruby 1.9 and newer +mb_chars+ returns +self+ because String is (mostly) encoding aware. This means that
-    # it becomes easy to run one version of your code on multiple Ruby versions.
-    #
-    # == Method chaining
-    #
-    # All the methods on the Chars proxy which normally return a string will return a Chars object. This allows
-    # method chaining on the result of any of these methods.
-    #
-    #   name.mb_chars.reverse.length # => 12
-    #
-    # == Interoperability and configuration
-    #
-    # The Chars object tries to be as interchangeable with String objects as possible: sorting and comparing between
-    # String and Char work like expected. The bang! methods change the internal string representation in the Chars
-    # object. Interoperability problems can be resolved easily with a +to_s+ call.
-    #
-    # For more information about the methods defined on the Chars proxy see ActiveSupport::Multibyte::Chars. For
-    # information about how to change the default Multibyte behavior see ActiveSupport::Multibyte.
-    def mb_chars
-      if ActiveSupport::Multibyte.proxy_class.consumes?(self)
-        ActiveSupport::Multibyte.proxy_class.new(self)
-      else
-        self
-      end
+  # == Multibyte proxy
+  #
+  # +mb_chars+ is a multibyte safe proxy for string methods.
+  #
+  # In Ruby 1.8 and older it creates and returns an instance of the ActiveSupport::Multibyte::Chars class which
+  # encapsulates the original string. A Unicode safe version of all the String methods are defined on this proxy
+  # class. If the proxy class doesn't respond to a certain method, it's forwarded to the encapsulated string.
+  #
+  #   name = 'Claus Müller'
+  #   name.reverse # => "rell??M sualC"
+  #   name.length  # => 13
+  #
+  #   name.mb_chars.reverse.to_s # => "rellüM sualC"
+  #   name.mb_chars.length       # => 12
+  #
+  # In Ruby 1.9 and newer +mb_chars+ returns +self+ because String is (mostly) encoding aware. This means that
+  # it becomes easy to run one version of your code on multiple Ruby versions.
+  #
+  # == Method chaining
+  #
+  # All the methods on the Chars proxy which normally return a string will return a Chars object. This allows
+  # method chaining on the result of any of these methods.
+  #
+  #   name.mb_chars.reverse.length # => 12
+  #
+  # == Interoperability and configuration
+  #
+  # The Chars object tries to be as interchangeable with String objects as possible: sorting and comparing between
+  # String and Char work like expected. The bang! methods change the internal string representation in the Chars
+  # object. Interoperability problems can be resolved easily with a +to_s+ call.
+  #
+  # For more information about the methods defined on the Chars proxy see ActiveSupport::Multibyte::Chars. For
+  # information about how to change the default Multibyte behavior see ActiveSupport::Multibyte.
+  def mb_chars
+    if ActiveSupport::Multibyte.proxy_class.consumes?(self)
+      ActiveSupport::Multibyte.proxy_class.new(self)
+    else
+      self
     end
+  end
 
-    def is_utf8?
-      case encoding
-      when Encoding::UTF_8
-        valid_encoding?
-      when Encoding::ASCII_8BIT, Encoding::US_ASCII
-        dup.force_encoding(Encoding::UTF_8).valid_encoding?
-      else
-        false
-      end
-    end
-  else
-    def mb_chars
-      if ActiveSupport::Multibyte.proxy_class.wants?(self)
-        ActiveSupport::Multibyte.proxy_class.new(self)
-      else
-        self
-      end
-    end
-
-    # Returns true if the string has UTF-8 semantics (a String used for purely byte resources is unlikely to have
-    # them), returns false otherwise.
-    def is_utf8?
-      ActiveSupport::Multibyte::Chars.consumes?(self)
+  def is_utf8?
+    case encoding
+    when Encoding::UTF_8
+      valid_encoding?
+    when Encoding::ASCII_8BIT, Encoding::US_ASCII
+      dup.force_encoding(Encoding::UTF_8).valid_encoding?
+    else
+      false
     end
   end
 end
diff --git a/activesupport/lib/active_support/core_ext/uri.rb b/activesupport/lib/active_support/core_ext/uri.rb
index ee991e3439..0b219ce44a 100644
--- a/activesupport/lib/active_support/core_ext/uri.rb
+++ b/activesupport/lib/active_support/core_ext/uri.rb
@@ -1,22 +1,18 @@
 # encoding: utf-8
 
-if RUBY_VERSION >= '1.9'
-  require 'uri'
+require 'uri'
+str = "\xE6\x97\xA5\xE6\x9C\xAC\xE8\xAA\x9E" # Ni-ho-nn-go in UTF-8, means Japanese.
+parser = URI::Parser.new
 
-  str = "\xE6\x97\xA5\xE6\x9C\xAC\xE8\xAA\x9E" # Ni-ho-nn-go in UTF-8, means Japanese.
-
-  parser = URI::Parser.new
-
-  unless str == parser.unescape(parser.escape(str))
-    URI::Parser.class_eval do
-      remove_method :unescape
-      def unescape(str, escaped = /%[a-fA-F\d]{2}/)
-        # TODO: Are we actually sure that ASCII == UTF-8?
-        # YK: My initial experiments say yes, but let's be sure please
-        enc = str.encoding
-        enc = Encoding::UTF_8 if enc == Encoding::US_ASCII
-        str.gsub(escaped) { [$&[1, 2].hex].pack('C') }.force_encoding(enc)
-      end
+unless str == parser.unescape(parser.escape(str))
+  URI::Parser.class_eval do
+    remove_method :unescape
+    def unescape(str, escaped = /%[a-fA-F\d]{2}/)
+      # TODO: Are we actually sure that ASCII == UTF-8?
+      # YK: My initial experiments say yes, but let's be sure please
+      enc = str.encoding
+      enc = Encoding::UTF_8 if enc == Encoding::US_ASCII
+      str.gsub(escaped) { [$&[1, 2].hex].pack('C') }.force_encoding(enc)
     end
   end
 end
diff --git a/activesupport/lib/active_support/multibyte/chars.rb b/activesupport/lib/active_support/multibyte/chars.rb
index b78d92f599..ba35b515f2 100644
--- a/activesupport/lib/active_support/multibyte/chars.rb
+++ b/activesupport/lib/active_support/multibyte/chars.rb
@@ -38,16 +38,10 @@ module ActiveSupport #:nodoc:
       alias to_s wrapped_string
       alias to_str wrapped_string
 
-      if RUBY_VERSION >= "1.9"
-        # Creates a new Chars instance by wrapping _string_.
-        def initialize(string)
-          @wrapped_string = string
-          @wrapped_string.force_encoding(Encoding::UTF_8) unless @wrapped_string.frozen?
-        end
-      else
-        def initialize(string) #:nodoc:
-          @wrapped_string = string
-        end
+      # Creates a new Chars instance by wrapping _string_.
+      def initialize(string)
+        @wrapped_string = string
+        @wrapped_string.force_encoding(Encoding::UTF_8) unless @wrapped_string.frozen?
       end
 
       # Forward all undefined methods to the wrapped string.
@@ -94,151 +88,8 @@ module ActiveSupport #:nodoc:
         @wrapped_string <=> other.to_s
       end
 
-      if RUBY_VERSION < "1.9"
-        # Returns +true+ if the Chars class can and should act as a proxy for the string _string_. Returns
-        # +false+ otherwise.
-        def self.wants?(string)
-          $KCODE == 'UTF8' && consumes?(string)
-        end
-
-        # Returns a new Chars object containing the _other_ object concatenated to the string.
-        #
-        # Example:
-        #   ('Café'.mb_chars + ' périferôl').to_s # => "Café périferôl"
-        def +(other)
-          chars(@wrapped_string + other)
-        end
-
-        # Like <tt>String#=~</tt> only it returns the character offset (in codepoints) instead of the byte offset.
-        #
-        # Example:
-        #   'Café périferôl'.mb_chars =~ /ô/ # => 12
-        def =~(other)
-          translate_offset(@wrapped_string =~ other)
-        end
-
-        # Inserts the passed string at specified codepoint offsets.
-        #
-        # Example:
-        #   'Café'.mb_chars.insert(4, ' périferôl').to_s # => "Café périferôl"
-        def insert(offset, fragment)
-          unpacked = Unicode.u_unpack(@wrapped_string)
-          unless offset > unpacked.length
-            @wrapped_string.replace(
-              Unicode.u_unpack(@wrapped_string).insert(offset, *Unicode.u_unpack(fragment)).pack('U*')
-            )
-          else
-            raise IndexError, "index #{offset} out of string"
-          end
-          self
-        end
-
-        # Returns +true+ if contained string contains _other_. Returns +false+ otherwise.
-        #
-        # Example:
-        #   'Café'.mb_chars.include?('é') # => true
-        def include?(other)
-          # We have to redefine this method because Enumerable defines it.
-          @wrapped_string.include?(other)
-        end
-
-        # Returns the position _needle_ in the string, counting in codepoints. Returns +nil+ if _needle_ isn't found.
-        #
-        # Example:
-        #   'Café périferôl'.mb_chars.index('ô')   # => 12
-        #   'Café périferôl'.mb_chars.index(/\w/u) # => 0
-        def index(needle, offset=0)
-          wrapped_offset = first(offset).wrapped_string.length
-          index = @wrapped_string.index(needle, wrapped_offset)
-          index ? (Unicode.u_unpack(@wrapped_string.slice(0...index)).size) : nil
-        end
-
-        # Returns the position _needle_ in the string, counting in
-        # codepoints, searching backward from _offset_ or the end of the
-        # string. Returns +nil+ if _needle_ isn't found.
-        #
-        # Example:
-        #   'Café périferôl'.mb_chars.rindex('é')   # => 6
-        #   'Café périferôl'.mb_chars.rindex(/\w/u) # => 13
-        def rindex(needle, offset=nil)
-          offset ||= length
-          wrapped_offset = first(offset).wrapped_string.length
-          index = @wrapped_string.rindex(needle, wrapped_offset)
-          index ? (Unicode.u_unpack(@wrapped_string.slice(0...index)).size) : nil
-        end
-
-        # Returns the number of codepoints in the string
-        def size
-          Unicode.u_unpack(@wrapped_string).size
-        end
-        alias_method :length, :size
-
-        # Strips entire range of Unicode whitespace from the right of the string.
-        def rstrip
-          chars(@wrapped_string.gsub(Unicode::TRAILERS_PAT, ''))
-        end
-
-        # Strips entire range of Unicode whitespace from the left of the string.
-        def lstrip
-          chars(@wrapped_string.gsub(Unicode::LEADERS_PAT, ''))
-        end
-
-        # Strips entire range of Unicode whitespace from the right and left of the string.
-        def strip
-          rstrip.lstrip
-        end
-
-        # Returns the codepoint of the first character in the string.
-        #
-        # Example:
-        #   'こんにちは'.mb_chars.ord # => 12371
-        def ord
-          Unicode.u_unpack(@wrapped_string)[0]
-        end
-
-        # Works just like <tt>String#rjust</tt>, only integer specifies characters instead of bytes.
-        #
-        # Example:
-        #
-        #   "¾ cup".mb_chars.rjust(8).to_s
-        #   # => "   ¾ cup"
-        #
-        #   "¾ cup".mb_chars.rjust(8, " ").to_s # Use non-breaking whitespace
-        #   # => "   ¾ cup"
-        def rjust(integer, padstr=' ')
-          justify(integer, :right, padstr)
-        end
-
-        # Works just like <tt>String#ljust</tt>, only integer specifies characters instead of bytes.
-        #
-        # Example:
-        #
-        #   "¾ cup".mb_chars.rjust(8).to_s
-        #   # => "¾ cup   "
-        #
-        #   "¾ cup".mb_chars.rjust(8, " ").to_s # Use non-breaking whitespace
-        #   # => "¾ cup   "
-        def ljust(integer, padstr=' ')
-          justify(integer, :left, padstr)
-        end
-
-        # Works just like <tt>String#center</tt>, only integer specifies characters instead of bytes.
-        #
-        # Example:
-        #
-        #   "¾ cup".mb_chars.center(8).to_s
-        #   # => " ¾ cup  "
-        #
-        #   "¾ cup".mb_chars.center(8, " ").to_s # Use non-breaking whitespace
-        #   # => " ¾ cup  "
-        def center(integer, padstr=' ')
-          justify(integer, :center, padstr)
-        end
-
-      else
-        def =~(other)
-          @wrapped_string =~ other
-        end
+      def =~(other)
+        @wrapped_string =~ other
       end
 
       # Works just like <tt>String#split</tt>, with the exception that the items in the resulting list are Chars
diff --git a/activesupport/lib/active_support/ordered_hash.rb b/activesupport/lib/active_support/ordered_hash.rb
index b0d4f2bd86..d4f309fbd7 100644
--- a/activesupport/lib/active_support/ordered_hash.rb
+++ b/activesupport/lib/active_support/ordered_hash.rb
@@ -51,172 +51,5 @@ module ActiveSupport
     def extractable_options?
       true
     end
-
-    # Hash is ordered in Ruby 1.9!
-    if RUBY_VERSION < '1.9'
-
-      # In MRI the Hash class is core and written in C. In particular, methods are
-      # programmed with explicit C function calls and polymorphism is not honored.
-      #
-      # For example, []= is crucial in this implementation to maintain the @keys
-      # array but hash.c invokes rb_hash_aset() originally. This prevents method
-      # reuse through inheritance and forces us to reimplement stuff.
-      #
-      # For instance, we cannot use the inherited #merge! because albeit the algorithm
-      # itself would work, our []= is not being called at all by the C code.
-
-      def initialize(*args, &block)
-        super
-        @keys = []
-      end
-
-      def self.[](*args)
-        ordered_hash = new
-
-        if (args.length == 1 && args.first.is_a?(Array))
-          args.first.each do |key_value_pair|
-            next unless (key_value_pair.is_a?(Array))
-            ordered_hash[key_value_pair[0]] = key_value_pair[1]
-          end
-
-          return ordered_hash
-        end
-
-        unless (args.size % 2 == 0)
-          raise ArgumentError.new("odd number of arguments for Hash")
-        end
-
-        args.each_with_index do |val, ind|
-          next if (ind % 2 != 0)
-          ordered_hash[val] = args[ind + 1]
-        end
-
-        ordered_hash
-      end
-
-      def initialize_copy(other)
-        super
-        # make a deep copy of keys
-        @keys = other.keys
-      end
-
-      def []=(key, value)
-        @keys << key unless has_key?(key)
-        super
-      end
-
-      def delete(key)
-        if has_key? key
-          index = @keys.index(key)
-          @keys.delete_at index
-        end
-        super
-      end
-
-      def delete_if
-        super
-        sync_keys!
-        self
-      end
-
-      def reject!
-        super
-        sync_keys!
-        self
-      end
-
-      def reject(&block)
-        dup.reject!(&block)
-      end
-
-      def keys
-        @keys.dup
-      end
-
-      def values
-        @keys.collect { |key| self[key] }
-      end
-
-      def to_hash
-        self
-      end
-
-      def to_a
-        @keys.map { |key| [ key, self[key] ] }
-      end
-
-      def each_key
-        return to_enum(:each_key) unless block_given?
-        @keys.each { |key| yield key }
-        self
-      end
-
-      def each_value
-        return to_enum(:each_value) unless block_given?
-        @keys.each { |key| yield self[key]}
-        self
-      end
-
-      def each
-        return to_enum(:each) unless block_given?
-        @keys.each {|key| yield [key, self[key]]}
-        self
-      end
-
-      def each_pair
-        return to_enum(:each_pair) unless block_given?
-        @keys.each {|key| yield key, self[key]}
-        self
-      end
-
-      alias_method :select, :find_all
-
-      def clear
-        super
-        @keys.clear
-        self
-      end
-
-      def shift
-        k = @keys.first
-        v = delete(k)
-        [k, v]
-      end
-
-      def merge!(other_hash)
-        if block_given?
-          other_hash.each { |k, v| self[k] = key?(k) ? yield(k, self[k], v) : v }
-        else
-          other_hash.each { |k, v| self[k] = v }
-        end
-        self
-      end
-
-      alias_method :update, :merge!
-
-      def merge(other_hash, &block)
-        dup.merge!(other_hash, &block)
-      end
-
-      # When replacing with another hash, the initial order of our keys must come from the other hash -ordered or not.
-      def replace(other)
-        super
-        @keys = other.keys
-        self
-      end
-
-      def invert
-        OrderedHash[self.to_a.map!{|key_value_pair| key_value_pair.reverse}]
-      end
-
-      def inspect
-        "#<OrderedHash #{super}>"
-      end
-
-      private
-        def sync_keys!
-          @keys.delete_if {|k| !has_key?(k)}
-        end
-    end
   end
 end
diff --git a/activesupport/lib/active_support/testing/performance/ruby.rb b/activesupport/lib/active_support/testing/performance/ruby.rb
index 7d6d047ef6..26731c6bd7 100644
--- a/activesupport/lib/active_support/testing/performance/ruby.rb
+++ b/activesupport/lib/active_support/testing/performance/ruby.rb
@@ -144,8 +144,6 @@ end
 
 if RUBY_VERSION.between?('1.9.2', '2.0')
   require 'active_support/testing/performance/ruby/yarv'
-elsif RUBY_VERSION.between?('1.8.6', '1.9')
-  require 'active_support/testing/performance/ruby/mri'
 else
   $stderr.puts 'Update your ruby interpreter to be able to run benchmarks.'
   exit
diff --git a/activesupport/lib/active_support/testing/performance/ruby/mri.rb b/activesupport/lib/active_support/testing/performance/ruby/mri.rb
deleted file mode 100644
index 142279dd6e..0000000000
--- a/activesupport/lib/active_support/testing/performance/ruby/mri.rb
+++ /dev/null
@@ -1,57 +0,0 @@
-module ActiveSupport
-  module Testing
-    module Performance
-      module Metrics
-        class Base
-          protected
-            # Ruby 1.8 + ruby-prof wrapper (enable/disable stats for Benchmarker)
-            if GC.respond_to?(:enable_stats)
-              def with_gc_stats
-                GC.enable_stats
-                GC.start
-                yield
-              ensure
-                GC.disable_stats
-              end
-            end
-        end
-
-        class Memory < DigitalInformationUnit
-          # Ruby 1.8 + ruby-prof wrapper
-          if RubyProf.respond_to?(:measure_memory)
-            def measure
-              RubyProf.measure_memory
-            end
-          end
-        end
-
-        class Objects < Amount
-          # Ruby 1.8 + ruby-prof wrapper
-          if RubyProf.respond_to?(:measure_allocations)
-            def measure
-              RubyProf.measure_allocations
-            end
-          end
-        end
-
-        class GcRuns < Amount
-          # Ruby 1.8 + ruby-prof wrapper
-          if RubyProf.respond_to?(:measure_gc_runs)
-            def measure
-              RubyProf.measure_gc_runs
-            end
-          end
-        end
-
-        class GcTime < Time
-          # Ruby 1.8 + ruby-prof wrapper
-          if RubyProf.respond_to?(:measure_gc_time)
-            def measure
-              RubyProf.measure_gc_time / 1000.0 / 1000.0
-            end
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/activesupport/test/abstract_unit.rb b/activesupport/test/abstract_unit.rb
index 0382739871..504ac3e9b9 100644
--- a/activesupport/test/abstract_unit.rb
+++ b/activesupport/test/abstract_unit.rb
@@ -11,15 +11,11 @@ lib = File.expand_path("#{File.dirname(__FILE__)}/../lib")
 $:.unshift(lib) unless $:.include?('lib') || $:.include?(lib)
 
 require 'active_support/core_ext/kernel/reporting'
-
 require 'active_support/core_ext/string/encoding'
-if "ruby".encoding_aware?
-  # These are the normal settings that will be set up by Railties
-  # TODO: Have these tests support other combinations of these values
-  silence_warnings do
-    Encoding.default_internal = "UTF-8"
-    Encoding.default_external = "UTF-8"
-  end
+
+silence_warnings do
+  Encoding.default_internal = "UTF-8"
+  Encoding.default_external = "UTF-8"
 end
 
 require 'test/unit'
@@ -30,9 +26,6 @@ silence_warnings { require 'mocha' }
 ENV['NO_RELOAD'] = '1'
 require 'active_support'
 
-# Include shims until we get off 1.8.6
-require 'active_support/ruby/shim' if RUBY_VERSION < '1.8.7'
-
 def uses_memcached(test_name)
   require 'memcache'
   begin
@@ -43,22 +36,5 @@ def uses_memcached(test_name)
   end
 end
 
-def with_kcode(code)
-  if RUBY_VERSION < '1.9'
-    begin
-      old_kcode, $KCODE = $KCODE, code
-      yield
-    ensure
-      $KCODE = old_kcode
-    end
-  else
-    yield
-  end
-end
-
 # Show backtraces for deprecated behavior for quicker cleanup.
-ActiveSupport::Deprecation.debug = true
-
-if RUBY_VERSION < '1.9'
-  $KCODE = 'UTF8'
-end
+ActiveSupport::Deprecation.debug = true
\ No newline at end of file
diff --git a/activesupport/test/core_ext/date_ext_test.rb b/activesupport/test/core_ext/date_ext_test.rb
index c040d86327..09d4765390 100644
--- a/activesupport/test/core_ext/date_ext_test.rb
+++ b/activesupport/test/core_ext/date_ext_test.rb
@@ -384,16 +384,6 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     end
   end
 
-  if RUBY_VERSION < '1.9'
-    def test_rfc3339
-      assert_equal('1980-02-28', Date.new(1980, 2, 28).rfc3339)
-    end
-
-    def test_iso8601
-      assert_equal('1980-02-28', Date.new(1980, 2, 28).iso8601)
-    end
-  end
-
   def test_today
     Date.stubs(:current).returns(Date.new(2000, 1, 1))
     assert_equal false, Date.new(1999, 12, 31).today?
diff --git a/activesupport/test/core_ext/hash_ext_test.rb b/activesupport/test/core_ext/hash_ext_test.rb
index eb8ed761da..dfa0cdb478 100644
--- a/activesupport/test/core_ext/hash_ext_test.rb
+++ b/activesupport/test/core_ext/hash_ext_test.rb
@@ -27,11 +27,7 @@ class HashExtTest < Test::Unit::TestCase
     @symbols = { :a  => 1, :b  => 2 }
     @mixed   = { :a  => 1, 'b' => 2 }
     @fixnums = {  0  => 1,  1  => 2 }
-    if RUBY_VERSION < '1.9.0'
-      @illegal_symbols = { "\0" => 1, "" => 2, [] => 3 }
-    else
-      @illegal_symbols = { [] => 3 }
-    end
+    @illegal_symbols = { [] => 3 }
   end
 
   def test_methods
diff --git a/activesupport/test/core_ext/range_ext_test.rb b/activesupport/test/core_ext/range_ext_test.rb
index 1424fa4aca..f4b773e5fb 100644
--- a/activesupport/test/core_ext/range_ext_test.rb
+++ b/activesupport/test/core_ext/range_ext_test.rb
@@ -63,15 +63,8 @@ class RangeTest < Test::Unit::TestCase
     assert_equal [1,3,5,7,9], array
   end
 
-  if RUBY_VERSION < '1.9'
-    def test_cover
-      assert((1..3).cover?(2))
-      assert !(1..3).cover?(4)
-    end
-  else
-    def test_cover_is_not_override
-      range = (1..3)
-      assert range.method(:include?) != range.method(:cover?)
-    end
+  def test_cover_is_not_override
+    range = (1..3)
+    assert range.method(:include?) != range.method(:cover?)
   end
 end
diff --git a/activesupport/test/core_ext/string_ext_test.rb b/activesupport/test/core_ext/string_ext_test.rb
index 47b9f68ed0..aeae2579b4 100644
--- a/activesupport/test/core_ext/string_ext_test.rb
+++ b/activesupport/test/core_ext/string_ext_test.rb
@@ -160,14 +160,6 @@ class StringInflectionsTest < Test::Unit::TestCase
     assert_equal 97, 'abc'.ord
   end
 
-  if RUBY_VERSION < '1.9'
-    def test_getbyte
-      assert_equal 97, 'a'.getbyte(0)
-      assert_equal 99, 'abc'.getbyte(2)
-      assert_nil   'abc'.getbyte(3)
-    end
-  end
-
   def test_string_to_time
     assert_equal Time.utc(2005, 2, 27, 23, 50), "2005-02-27 23:50".to_time
     assert_equal Time.local(2005, 2, 27, 23, 50), "2005-02-27 23:50".to_time(:local)
@@ -287,21 +279,9 @@ class StringInflectionsTest < Test::Unit::TestCase
     assert_equal "Hello Big[...]", "Hello Big World!".truncate(15, :omission => "[...]", :separator => ' ')
   end
 
-  if RUBY_VERSION < '1.9.0'
-    def test_truncate_multibyte
-      with_kcode 'none' do
-        assert_equal "\354\225\210\353\205\225\355...", "\354\225\210\353\205\225\355\225\230\354\204\270\354\232\224".truncate(10)
-      end
-      with_kcode 'u' do
-        assert_equal "\354\225\204\353\246\254\353\236\221 \354\225\204\353\246\254 ...",
-          "\354\225\204\353\246\254\353\236\221 \354\225\204\353\246\254 \354\225\204\353\235\274\353\246\254\354\230\244".truncate(10)
-      end
-    end
-  else
-    def test_truncate_multibyte
-      assert_equal "\354\225\204\353\246\254\353\236\221 \354\225\204\353\246\254 ...".force_encoding('UTF-8'),
-        "\354\225\204\353\246\254\353\236\221 \354\225\204\353\246\254 \354\225\204\353\235\274\353\246\254\354\230\244".force_encoding('UTF-8').truncate(10)
-    end
+  def test_truncate_multibyte
+    assert_equal "\354\225\204\353\246\254\353\236\221 \354\225\204\353\246\254 ...".force_encoding('UTF-8'),
+      "\354\225\204\353\246\254\353\236\221 \354\225\204\353\246\254 \354\225\204\353\235\274\353\246\254\354\230\244".force_encoding('UTF-8').truncate(10)
   end
 
   def test_constantize
@@ -338,22 +318,8 @@ class CoreExtStringMultibyteTest < ActiveSupport::TestCase
     assert !BYTE_STRING.is_utf8?
   end
 
-  if RUBY_VERSION < '1.9'
-    def test_mb_chars_returns_self_when_kcode_not_set
-      with_kcode('none') do
-        assert_kind_of String, UNICODE_STRING.mb_chars
-      end
-    end
-
-    def test_mb_chars_returns_an_instance_of_the_chars_proxy_when_kcode_utf8
-      with_kcode('UTF8') do
-        assert_kind_of ActiveSupport::Multibyte.proxy_class, UNICODE_STRING.mb_chars
-      end
-    end
-  else
-    def test_mb_chars_returns_instance_of_proxy_class
-      assert_kind_of ActiveSupport::Multibyte.proxy_class, UNICODE_STRING.mb_chars
-    end
+  def test_mb_chars_returns_instance_of_proxy_class
+    assert_kind_of ActiveSupport::Multibyte.proxy_class, UNICODE_STRING.mb_chars
   end
 end
 
@@ -479,11 +445,7 @@ class OutputSafetyTest < ActiveSupport::TestCase
   end
 
   test 'knows whether it is encoding aware' do
-    if RUBY_VERSION >= "1.9"
-      assert 'ruby'.encoding_aware?
-    else
-      assert !'ruby'.encoding_aware?
-    end
+    assert 'ruby'.encoding_aware?
   end
 
   test "call to_param returns a normal string" do
diff --git a/activesupport/test/core_ext/time_with_zone_test.rb b/activesupport/test/core_ext/time_with_zone_test.rb
index 9d9e411c28..04f5ea85a8 100644
--- a/activesupport/test/core_ext/time_with_zone_test.rb
+++ b/activesupport/test/core_ext/time_with_zone_test.rb
@@ -448,9 +448,8 @@ class TimeWithZoneTest < Test::Unit::TestCase
   end
 
   def test_ruby_19_weekday_name_query_methods
-    ruby_19_or_greater = RUBY_VERSION >= '1.9'
     %w(sunday? monday? tuesday? wednesday? thursday? friday? saturday?).each do |name|
-      assert_equal ruby_19_or_greater, @twz.respond_to?(name)
+      assert_respond_to @twz, name
     end
   end
 
diff --git a/activesupport/test/json/encoding_test.rb b/activesupport/test/json/encoding_test.rb
index 8cf1a54a99..ad9a497515 100644
--- a/activesupport/test/json/encoding_test.rb
+++ b/activesupport/test/json/encoding_test.rb
@@ -88,25 +88,21 @@ class TestJSONEncoding < Test::Unit::TestCase
     assert_equal %({\"a\":\"b\",\"c\":\"d\"}), sorted_json(ActiveSupport::JSON.encode(:a => :b, :c => :d))
   end
 
-  def test_utf8_string_encoded_properly_when_kcode_is_utf8
-    with_kcode 'UTF8' do
-      result = ActiveSupport::JSON.encode('€2.99')
-      assert_equal '"\\u20ac2.99"', result
-      assert_equal(Encoding::UTF_8, result.encoding) if result.respond_to?(:encoding)
+  def test_utf8_string_encoded_properly
+    result = ActiveSupport::JSON.encode('€2.99')
+    assert_equal '"\\u20ac2.99"', result
+    assert_equal(Encoding::UTF_8, result.encoding) if result.respond_to?(:encoding)
 
-      result = ActiveSupport::JSON.encode('✎☺')
-      assert_equal '"\\u270e\\u263a"', result
-      assert_equal(Encoding::UTF_8, result.encoding) if result.respond_to?(:encoding)
-    end
+    result = ActiveSupport::JSON.encode('✎☺')
+    assert_equal '"\\u270e\\u263a"', result
+    assert_equal(Encoding::UTF_8, result.encoding) if result.respond_to?(:encoding)
   end
 
-  if '1.9'.respond_to?(:force_encoding)
-    def test_non_utf8_string_transcodes
-      s = '二'.encode('Shift_JIS')
-      result = ActiveSupport::JSON.encode(s)
-      assert_equal '"\\u4e8c"', result
-      assert_equal Encoding::UTF_8, result.encoding
-    end
+  def test_non_utf8_string_transcodes
+    s = '二'.encode('Shift_JIS')
+    result = ActiveSupport::JSON.encode(s)
+    assert_equal '"\\u4e8c"', result
+    assert_equal Encoding::UTF_8, result.encoding
   end
 
   def test_exception_raised_when_encoding_circular_reference_in_array
diff --git a/activesupport/test/multibyte_chars_test.rb b/activesupport/test/multibyte_chars_test.rb
index bfff10fff2..ba04638354 100644
--- a/activesupport/test/multibyte_chars_test.rb
+++ b/activesupport/test/multibyte_chars_test.rb
@@ -101,15 +101,8 @@ class MultibyteCharsUTF8BehaviourTest < Test::Unit::TestCase
 
   def setup
     @chars = UNICODE_STRING.dup.mb_chars
-
-    if RUBY_VERSION < '1.9'
-      # Multibyte support all kinds of whitespace (ie. NEWLINE, SPACE, EM SPACE)
-      @whitespace = "\n\t#{[32, 8195].pack('U*')}"
-    else
-      # Ruby 1.9 only supports basic whitespace
-      @whitespace = "\n\t "
-    end
-
+    # Ruby 1.9 only supports basic whitespace
+    @whitespace = "\n\t "
     @byte_order_mark = [65279].pack('U')
   end
 
diff --git a/activesupport/test/multibyte_utils_test.rb b/activesupport/test/multibyte_utils_test.rb
index 0a2f20d282..9a8f7050fe 100644
--- a/activesupport/test/multibyte_utils_test.rb
+++ b/activesupport/test/multibyte_utils_test.rb
@@ -56,37 +56,9 @@ class MultibyteUtilsTest < ActiveSupport::TestCase
     end
   end
 
-  if RUBY_VERSION < '1.9'
-    test "clean leaves ASCII strings intact" do
-      with_encoding('None') do
-        [
-          'word', "\270\236\010\210\245"
-        ].each do |string|
-          assert_equal string, ActiveSupport::Multibyte.clean(string)
-        end
-      end
-    end
-
-    test "clean cleans invalid characters from UTF-8 encoded strings" do
-      with_encoding('UTF8') do
-        cleaned_utf8 = [8].pack('C*')
-        assert_equal example('valid UTF-8'), ActiveSupport::Multibyte.clean(example('valid UTF-8'))
-        assert_equal cleaned_utf8, ActiveSupport::Multibyte.clean(example('invalid UTF-8'))
-      end
-    end
-
-    test "clean cleans invalid characters from Shift-JIS encoded strings" do
-      with_encoding('SJIS') do
-        cleaned_sjis = [184, 0, 136, 165].pack('C*')
-        assert_equal example('valid Shift-JIS'), ActiveSupport::Multibyte.clean(example('valid Shift-JIS'))
-        assert_equal cleaned_sjis, ActiveSupport::Multibyte.clean(example('invalid Shift-JIS'))
-      end
-    end
-  else
-    test "clean is a no-op" do
-      with_encoding('UTF8') do
-        assert_equal example('invalid Shift-JIS'), ActiveSupport::Multibyte.clean(example('invalid Shift-JIS'))
-      end
+  test "clean is a no-op" do
+    with_encoding('UTF8') do
+      assert_equal example('invalid Shift-JIS'), ActiveSupport::Multibyte.clean(example('invalid Shift-JIS'))
     end
   end
 
@@ -119,19 +91,13 @@ class MultibyteUtilsTest < ActiveSupport::TestCase
     end
   end
 
-  if 'string'.respond_to?(:encoding)
-    KCODE_TO_ENCODING = Hash.new(Encoding::BINARY).
-      update('UTF8' => Encoding::UTF_8, 'SJIS' => Encoding::Shift_JIS)
+  KCODE_TO_ENCODING = Hash.new(Encoding::BINARY).
+    update('UTF8' => Encoding::UTF_8, 'SJIS' => Encoding::Shift_JIS)
 
-    def with_encoding(enc)
-      before = Encoding.default_external
-      silence_warnings { Encoding.default_external = KCODE_TO_ENCODING[enc] }
-
-      yield
-
-      silence_warnings { Encoding.default_external = before }
-    end
-  else
-    alias with_encoding with_kcode
+  def with_encoding(enc)
+    before = Encoding.default_external
+    silence_warnings { Encoding.default_external = KCODE_TO_ENCODING[enc] }
+    yield
+    silence_warnings { Encoding.default_external = before }
   end
 end
diff --git a/activesupport/test/ordered_hash_test.rb b/activesupport/test/ordered_hash_test.rb
index 0b5f912dc4..8119b36491 100644
--- a/activesupport/test/ordered_hash_test.rb
+++ b/activesupport/test/ordered_hash_test.rb
@@ -81,24 +81,21 @@ class OrderedHashTest < Test::Unit::TestCase
     keys = []
     assert_equal @ordered_hash, @ordered_hash.each_key { |k| keys << k }
     assert_equal @keys, keys
-    expected_class = RUBY_VERSION < '1.9' ? Enumerable::Enumerator : Enumerator
-    assert_kind_of expected_class, @ordered_hash.each_key
+    assert_kind_of Enumerator, @ordered_hash.each_key
   end
 
   def test_each_value
     values = []
     assert_equal @ordered_hash, @ordered_hash.each_value { |v| values << v }
     assert_equal @values, values
-    expected_class = RUBY_VERSION < '1.9' ? Enumerable::Enumerator : Enumerator
-    assert_kind_of expected_class, @ordered_hash.each_value
+    assert_kind_of Enumerator, @ordered_hash.each_value
   end
 
   def test_each
     values = []
     assert_equal @ordered_hash, @ordered_hash.each {|key, value| values << value}
     assert_equal @values, values
-    expected_class = RUBY_VERSION < '1.9' ? Enumerable::Enumerator : Enumerator
-    assert_kind_of expected_class, @ordered_hash.each
+    assert_kind_of Enumerator, @ordered_hash.each
   end
 
   def test_each_with_index
@@ -114,9 +111,7 @@ class OrderedHashTest < Test::Unit::TestCase
     end
     assert_equal @values, values
     assert_equal @keys, keys
-
-    expected_class = RUBY_VERSION < '1.9' ? Enumerable::Enumerator : Enumerator
-    assert_kind_of expected_class, @ordered_hash.each_pair
+    assert_kind_of Enumerator, @ordered_hash.each_pair
   end
 
   def test_find_all