Why were amendments added?

The first ten amendments were added to address Anti-Federalist concerns about individual liberty raised during the ratification debate of 1787 through 1790, and to honor promises made by Federalist leaders to secure ratification in closely divided states like Massachusetts, Virginia, and New York. The original Constitution submitted to the states on September 17, 1787 contained no general bill of rights. Federalists argued that one was unnecessary because the federal government had only enumerated powers and could not encroach on liberties not granted to it. James Wilson made this case in his October 6, 1787 State House speech in Philadelphia, and Alexander Hamilton repeated it in Federalist No. 84.

Anti-Federalists answered that without explicit guarantees the federal government would inevitably expand and that English liberty had always rested on charters from Magna Carta of 1215 through the English Bill of Rights of 1689. They cited examples from state declarations such as George Mason's Virginia Declaration of Rights of June 12, 1776, the Pennsylvania Declaration of Rights of 1776, and the Massachusetts Declaration of Rights of 1780 drafted by John Adams. The pressure forced compromise during ratification. Massachusetts ratified on February 6, 1788 by 187 to 168 only after Federalists agreed to recommend amendments to the new Congress. Virginia followed on June 25, 1788 with a list of 40 proposed amendments, including 20 on rights. New York ratified on July 26, 1788 with similar recommendations.

North Carolina rejected the Constitution outright in August 1788, then reversed course on November 21, 1789 after Madison's draft amendments were before the states. James Madison, who had initially considered a bill of rights superfluous, came around as a candidate for the First Congress. He had promised his Virginia constituents he would push for amendments, and he had concluded that codifying rights would defuse Anti-Federalist anxiety. On June 8, 1789 he proposed 17 amendments in a long speech to the House. Congress reduced them to 12 and sent them to the states on September 25, 1789. Ten were ratified together by December 15, 1791.

The first proposed amendment on apportionment was never ratified. The second, on congressional pay, sat dormant until 1992 when it became the Twenty-Seventh Amendment. The Bill of Rights therefore did not just calm Anti-Federalist fears in 1791. It also institutionalized the principle that constitutional design should explicitly protect individual liberty against majority government, a principle that has shaped every later amendment expanding rights.