the building in the US city of Philadelphia where the Declaration of Independence was written and signed in 1776 by the Continental Congress, and where the US Constitution was written and approved in 1787 by the Federal Constitution Convention. It is the most important building in America's history. It was built in 1732 as the Pennsylvania State House. The Liberty Bell is also there. Independence Hall is on Chestnut Street in Independence National Historic Park. It was made a World Heritage Site in 1979.