What year was the U.S. Constitution ratified?

The U.S. Constitution was ratified in 1788, marking a significant moment in the formation of the United States government. Following its drafting at the Constitutional Convention in Philadelphia in 1787, the document required approval from nine states to become effective. By June 21, 1788, with the ratification of New Hampshire, the Constitution had met this requirement. Although it took until 1791 for the Bill of Rights to be ratified, the foundational framework of the government was established in the earlier year. The other years listed—1776, 1791, and 1775—are significant in American history for different reasons, such as the signing of the Declaration of Independence in 1776 and other foundational events, but they are not related to the ratification of the Constitution itself.