Key facts
27
Amendments to the Constitution
National Archives
December 15, 1791
Date the Bill of Rights was ratified
National Archives
38 of 50
States needed to ratify an amendment (three-fourths)
Art. V
What the Constitution does
The ConstitutionThe highest law of a country or state. It sets up the government, divides its powers and protects rights, and the United States and each state have their own.Read more in the glossary was signed on September 17, 1787, and its seven articles set up the federal government. Article I creates Congress, Article II the presidency and Article III the federal courts. Article IV covers how the states relate to each other and to the federal government. Article V explains how to amend the Constitution, and Article VI makes it the supreme law. Article VII said it would take effect once conventions in 9 states ratified it.
What the Bill of Rights protects
Congress proposed 12 amendments on September 25, 1789. The states ratified 10 of them on December 15, 1791, and those 10 are the Bill of Rights. They protect freedom of religion, speech, the press and assembly, and the right to petition the government. They also protect the right to keep and bear arms, bar unreasonable searches and give rights to people accused of crimes, such as a jury trial and a lawyer.
Do these rights limit state governments?
At first, the Bill of Rights limited only the federal government. The Supreme Court said so in Barron v. Baltimore (1833). After the Civil War, the Fourteenth AmendmentA change to a constitution, law or bill. In a legislature, an amendment is also a proposed change that members vote on before passing a bill.Read more in the glossary was ratified on July 9, 1868. It bars any state from depriving a person of “life, liberty, or property, without due process of law.” The Supreme Court has held that this clause applies the Bill of Rights to the states, with only “a handful” of exceptions.
How the Constitution can change
Article V sets two steps. First, an amendment is proposed by a two-thirds vote of both houses of Congress, or by a convention Congress calls when two-thirds of state legislatures apply. Second, three-fourths of the states, now 38 of 50, must ratify it through their legislatures or conventions, as Congress chooses. All 27 amendments so far were proposed by Congress. The president has no formal role, and the Archivist of the United States certifies the result.
27 amendments so far
The National Archives lists 27 amendments. After the Bill of Rights, 17 more were added. Some changed how officials are chosen. The Seventeenth Amendment (1913), for example, provides for senators elected by the people. The Twenty-first Amendment (1933) repealed the Eighteenth. The most recent, the Twenty-seventh, delays any change in congressional pay until after the next House election. It was ratified on May 7, 1992.
The Congress, whenever two thirds of both Houses shall deem it necessary, shall propose Amendments to this Constitution
Questions people ask
How many amendments does the Constitution have?
Does the Bill of Rights apply to state governments?
Can Congress change the Constitution by passing a law?
Has a convention ever proposed an amendment?
Sources
Checked November 4, 2026. Primary sources first, then official records, then nonpartisan research.
How these facts were checked: our promise. Every substantive fix is listed on the corrections page.
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