Fairground Park is a municipal park in St. Louis, Missouri, that opened in 1908. It was originally a privately owned facility, first used by the St. Louis Agricultural and Mechanical Association for the St. Louis Exposition from 1856 through 1902. However, the Civil War interrupted the annual fair when the Fairgrounds were used as a Union encampment known as Benton Barracks. The annual exposition ceased in 1902 as preparations for the 1904 World's Fair began.