The Centennial International Exhibition of 1876, the first official World's Fair to be held 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. Officially named the International Exhibition of Arts, Manufactures, and Products of the Soil and Mine, it was held in Fairmount Park along the Schuylkill River on fairgrounds designed by Herman J. Schwarzmann. Nearly 10 million visitors attended the exposition, and 37 countries participated in it.
Philadelphia passed an ordinance that authorized Mayor William S. Stokley to appoint 500 men as Centennial Guards for the exposition. Among soldiers and local men hired by the city was Frank Geyer, best known for investigating one of America's first serial killers, H. H. Holmes. Centennial Guards policed exhibits, kept the peace, reunited lost children, and received, recorded, and when possible, returned lost items, the most unusual of which were front hair pieces and false teeth. Guards were required to live onsite and were housed at six police stations strategically located throughout the Exposition. A magistrate's office and courtroom were located at the only two-story police station located on the grounds and was used to conduct prisoner hearings. Officers slept in cramped quarters, which fostered health issues. Eight guards died while working the Exposition, six from typhoid fever, one from smallpox, and one from organic disease of the heart.