Exposition Park was the name given to three historic stadiums, located in what is today Pittsburgh, Pennsylvania. The fields were used mainly for professional baseball and American football from c. 1879 to c. 1915. The ballparks were initially located on the north side of the Allegheny River in Allegheny City, Pennsylvania. The city was annexed into Pittsburgh i…Exposition Park was the name given to three historic stadiums, located in what is today Pittsburgh, Pennsylvania. The fields were used mainly for professional baseball and American football from c. 1879 to c. 1915. The ballparks were initially located on the north side of the Allegheny River in Allegheny City, Pennsylvania. The city was annexed into Pittsburgh in 1907, which became the city's North Side, located across from Pittsburgh's downtown area. Due to flooding from the nearby Allegheny River, the three stadiums' exact locations varied somewhat. The final version of the ballpark was between the eventual sites of Three Rivers Stadium and PNC Park.