The first ten amendments to the U.S. Constitution are collectively called the Bill of Rights.
Congress originally proposed twelve amendments on September 25, 1789. The states ratified ten of them on December 15, 1791, and those ten became Amendments One through Ten. The unratified articles concerned congressional apportionment and congressional pay; the pay proposal eventually became the Twenty-seventh Amendment in 1992.
James Madison played the leading role in shaping the amendments. They responded partly to Anti-Federalist criticism that the Constitution did not sufficiently protect individual liberties. The amendments address freedoms of religion, speech, press, assembly, and petition, along with protections involving searches, trials, punishment, and federalism.
The Bill of Rights was added to the Constitution rather than replacing it. Its provisions remain part of the same constitutional document created by the 1787 convention.