Philadelphia is known as the scene of many great historical events connected with the founding of the U.S.A. The declaration of independence was signed here by Thomas Jefferson in 1776. After that, the Constitution of the United States of America was formed, the first Congress met in Philadelphia, and this continued to be the U.S. capital for the next ten years. It has the most historic square mile in America: Independence National Historical Park, Independence Hall, Congress Hall, Liberty Bell and the Betsy Ross House, where the first American Flag of the original 13 states was made. City Hall is the nation's largest municipal building.