Philadelphia hosted the 1876 United States Centennial Exposition, the world's fair celebrating the nation's 100th anniversary.
The exposition ran from May 10 to November 10, 1876, in Fairmount Park along the Schuylkill River. It was the first official world's fair held in the United States and formed the centerpiece of the country's centennial observances.
The fair displayed industrial products, artworks, machinery, agricultural goods, and inventions from the United States and other countries. Nearly 10 million people attended, a remarkable total for the period. Its buildings included Memorial Hall and Machinery Hall, while exhibits introduced many visitors to technologies such as the telephone and improved sewing machines.
Philadelphia was selected because of its central role in the founding era: the Declaration of Independence had been adopted there in 1776, and the city had served as an early national capital. The 1876 event is distinct from Philadelphia's 1926 Sesquicentennial Exposition, which marked 150 years and is the subject of a separate anniversary question.