Bill of Rights, in the United States, the first 10 amendments to the U.S. Constitution, which were adopted as a single unit on December 15, 1791, and which constitute a collection of mutually reinforcing guarantees of individual rights and of limitations on federal and state governments.

The framers also allowed for changes to the Constitution, outlining the procedures required to amend it in Article V. Proposed by Congress in September 1789 and adopted in 1791, the first 10 amendments to the Constitution, known collectively as the Bill of Rights, place limits on the federal and state governments’ power to curtail individual rights and freedoms.