The first ten amendments to the United States Constitution are called the Bill of Rights.
They were proposed by Congress in 1789 and ratified by the states in 1791. The amendments protect freedoms and establish limits on federal power, including freedom of speech, religious exercise, press, assembly, and petition. They also address criminal-procedure rights and the relationship between government and the people.
James Madison introduced the proposed amendments in the First Congress. He drew on concerns raised during the Constitution’s ratification debates, especially worries that the new federal government might become too powerful. The original proposal contained twelve amendments, but two were not ratified at that time; the ten that took effect became the Bill of Rights.
The Bill of Rights originally constrained the federal government. Through later constitutional interpretation, many of its protections were applied to state governments through the Fourteenth Amendment.