The MacArthur Bridge is a truss bridge that connects St. Louis, Missouri and East St. Louis, Illinois over the Mississippi River. The bridge was initially called the "St. Louis Municipal Bridge" and known popularly as the "Free Bridge" due to the original lack of tolls. Tolls were added for auto traffic beginning in 1932. In 1942, the bridge was renamed for Douglas MacArthur. The bridge was constructed to break the monopoly of the Terminal Railroad Association, which controlled two other bridges at St. Louis and charged what were viewed as unreasonable tolls.

The Terminal Railroad Association of St. Louis is a Class III switching and terminal railroad that handles traffic in the St. Louis metropolitan area. It is co-owned by five of the six Class I railroads that reach the city: BNSF, Canadian National, CSX, Norfolk Southern and Union Pacific. The railroad also serves Amtrak and Canadian Pacific Kansas City.