Where was the U.S. Constitution signed in 1787?

The U.S. Constitution was signed at Independence Hall in Philadelphia in 1787.

The signing took place on September 17, 1787, at the Pennsylvania State House, the building now known as Independence Hall. Thirty-nine delegates endorsed the completed Constitution there after nearly four months of debate at the Constitutional Convention. The convention had begun on May 25 and included delegates from twelve states; Rhode Island did not send delegates.

Independence Hall was already associated with the founding era because the Declaration of Independence had been adopted there in 1776. The building therefore hosted two central events in the creation of the United States, although the documents were produced eleven years apart and under different political circumstances.

The Constitution did not take effect immediately upon signing. It required ratification by nine states, which occurred in June 1788 when New Hampshire became the ninth. The new federal government began operations in 1789. Philadelphia served as the national capital until the government moved to Washington, D.C., in 1800.