It is also usual for several similar resolutions to be proposed on causes that have substantial public and legislative support. Congress has submitted 33 constitutional amendments to the states for ratification since 1789. 27 of these have been ratified. Three others were rejected by special votes of both Houses - one was rejected by the Senate but not by the House, and one by the House but not by the Senate. These are called "negatives" because they fail to amend the Constitution. The final resolution, which changed the way congressional elections are held, was approved by Congress and the President.
The first 10 amendments, collectively known as the Bill of Rights, were adopted in 1791 and 1972 years after the original drafting of the Constitution. The 11th amendment, which limits federal power, was proposed in 1794 but not ratified until 1971. The 12th amendment, which defines electoral procedures for electing Senators, was proposed in 1866 but did not become effective until 1913. The 13th amendment, which abolishes slavery, was proposed in 1865 but not ratified by the necessary three-fourths vote of the states until 1992. The 14th amendment, which guarantees certain rights to all citizens including the right to vote, was proposed in 1866 but not ratified by the necessary three-fourths vote of the states until 1968.
Since 1789, about 10,000 amendments have been offered in Congress, with only a small number of those receiving enough support to proceed through the constitutional ratification process.
The Constitution can be amended via a constitutional convention or through the passage of state constitutions. Amending the Constitution requires the approval of three-quarters of the states, or when the Constitution is revised via a constitutional convention, it requires the approval of the legislatures of at least nine states. The last amendment was passed in 1992, but many recent changes have been made to state constitutions without being formalized in law.
Amendments are usually proposed by Congress or its committees, often as part of larger legislation dealing with a particular issue. Sometimes amendments are adopted by Congress as stand-alone measures. For example, the 23rd Amendment eliminated congressional pay increases for members of Congress and their staffs. It was adopted in 1997 without any other related legislation.
Amendments may also be proposed by states' rights advocates who believe that certain provisions of the Constitution limit federal power or encourage democratic governance, such as in New Jersey where a bill of rights was proposed in 1678 and ratified in 1776.
Since the Constitution's inception on March 4, 1789, the United States Congress has proposed and sent to the states for approval thirty-three amendments to the United States Constitution. Twenty-seven of them have been approved by the required number of states and are now included into the Constitution. The other six amendments, which affected how Congress is elected or how federal elections are held, remain in effect today but are expected to be superseded by subsequent amendments that have yet to be proposed.
The first ten amendments, collectively called the Bill of Rights, were added to the Constitution during the First Federal Congress (1789–1791). The remaining 23 amendments were subsequently adopted over the course of several decades beginning with the Ninth Amendment in 1947.
Each amendment must be ratified by the legislatures of three-fourths of the states to become part of the Constitution. As of 2017, twenty-seven of the amendments have been ratified, while six others have not yet been ratified by the necessary number of states.
Amendments are usually proposed after much debate within the legislative body concerned with addressing issues such as strengthening protections afforded under the Constitution's original framework or reducing constitutional barriers to actions taken by that body. Each amendment requires ratification by the legislatures of three-fourths of the states before it can take effect.