Interior View of the Main Pavilion, Centennial Exhibition, Philadelphia (w/c on paper)

The Centennial International Exhibition of 1876, the first official World's Fair in the United States, was held in Philadelphia, Pennsylvania, from May 10 to November 10, 1876, to celebrate the 100th anniversary of the signing of the Declaration of Independence in Philadelphia. It was officially the International Exhibition of Arts, Manufactures and Products of the Soil and Mine. A temporary structure, the Main Building was the largest building in the world by area, enclosing 21.5 acres (8.7 ha). It was constructed using prefabricated parts, with a wood and iron frame resting on 672 stone piers, and took eighteen months to complete. Glass was used between the frames to let in light. Inside, the central avenue was 120 ft (37 m) wide, 1,832 ft (558 m) long, and 75 ft (23 m) high. A 75-foot-tall (23 m) tower stood at each of the building's corners. Exhibits from the United States were placed in the center of the building, and foreign exhibits were arranged around the center, based on the nation's distance from the United States. Exhibits inside the Main Building dealt with mining, metallurgy, manufacturing, education and science.