The Merchants Exchange Building was a building at Third Street at Chestnut and Pine in St. Louis, Missouri, from 1875 to 1958 that housed the St. Louis Merchants Exchange and hosted the 1876 Democratic National Convention. The building was designed by Francis Lee and Thomas Annan who placed second in a competition for the structure (the winner was George I. Barnett but his work was considered too expensive. The $2 million venue measured 235 by 187 ft (72 by 57 m) by 187 feet (57 m) and was actually two separate buildings.