Which world's fair marked the United States' 1876 centennial celebration in Philadelphia?

The Centennial Exposition marked the United States' 1876 centennial celebration in Philadelphia.

Officially called the International Exhibition of Arts, Manufactures, and Products of the Soil and Mine, the fair ran from May 10 through November 10, 1876. It celebrated the 100th anniversary of the adoption of the Declaration of Independence and was held in Fairmount Park.

The exposition was the first official world's fair in the United States. Nearly 10 million people attended, and 37 countries participated. Exhibits displayed industrial products, scientific developments, agricultural equipment, artworks, and new inventions.

Visitors encountered Alexander Graham Bell's telephone, Thomas Edison's automatic telegraph, sewing machines, and an elevated steam-powered monorail. The fair is sometimes confused with the 1926 Sesquicentennial Exposition and the 1976 Bicentennial celebrations; those marked the 150th and 200th anniversaries, respectively.