In which city was the U.S. Constitution signed in 1787?

The U.S. Constitution was signed in Philadelphia in 1787.

Delegates met at the Pennsylvania State House, now called Independence Hall, for the Constitutional Convention. The convention began on May 25, 1787, and the final document was signed there on September 17. Philadelphia was then the largest city in the United States and an important center of commerce and politics.

The convention had originally been called to improve the Articles of Confederation, but the delegates eventually designed an entirely new national framework. The Constitution divided power among legislative, executive, and judicial branches and created a federal system shared by the national government and the states.

Philadelphia was also the meeting place for the Continental Congress during much of the Revolutionary era. It served as the U.S. capital from 1790 until 1800, when the federal government moved to Washington, D.C. The Constitution itself did not name Philadelphia as a permanent capital.