When Virginia, a large and influential state, threatened not to ratify the Constitution, James Madison promised to make a Bill of Rights the first order of business for the First Federal Congress. Although Madison initially did not believe a Bill of Rights was necessary, he made this promise to address the concerns of Anti-Federalists like George Mason and Patrick Henry, who feared the Constitution lacked protections for individual liberties. Following Virginia's ratification, Madison introduced amendments in Congress, which eventually became the Bill of Rights, ratified in 1791.

This promise was crucial in securing Virginia's approval of the Constitution on June 25, 1788, four days after the Constitution was officially ratified by the ninth state, ensuring the establishment of the new federal government.