Delegates to the Constitutional Convention disagreed over the wisdom of listing specific rights within the U.S. Constitution, but anti-Federalists insisted individual liberties—including the freedoms of speech, religion, and assembly—needed protection from the new national government. Delegates promised these protections to entice opposing states to ratify the U.S. Constitution. Fulfilling that promise, the members of the First Congress (1789–1791) proposed 12 amendments to the original U.S. Constitution. Ten of them were swiftly ratified by the states and became known as the Bill of Rights.
The conventions of a number of the states, having at the time of their adopting the Constitution, expressed a desire, in order to prevent misconstruction or abuse of its powers, that further declaratory and restrictive clauses should be added
Preamble, Bill of Rights, 1789