In what building did delegates sign the U.S. Constitution in 1787?

Delegates signed the U.S. Constitution in Independence Hall in Philadelphia in 1787.

At the time, the building was commonly known as the Pennsylvania State House. The Constitutional Convention met there from May 25 through September 17, 1787, with George Washington presiding over the delegates’ sessions.

The same building had hosted the Continental Congress and the adoption of the Declaration of Independence in 1776. Its earlier name explains why historical accounts may refer to the Pennsylvania State House rather than Independence Hall. The building was renamed in the 19th century as its association with American independence grew.

Thirty-nine delegates signed the Constitution on September 17, 1787. The document then went to the states for ratification, requiring approval by nine states before taking effect. Independence Hall is now part of Independence National Historical Park and is a major landmark of the founding era.