Though the city of St. Louis is located on the Missouri side of the Mississippi River, for the railroads, the St. Louis Gateway extends into Illinois, north and south along both sides of the river. Two factors conspired against St. Louiss aspiration to become the preeminent rail center of the 19th-century American Midwest: there was no bridge across the Mississippi, and Missouris loyalty to the Union during the Civil War was suspect. Chicago beat out St. Louis to attain the regions top railroad billing. Fast forward to the 1970s, when the Gateway Arch, dedicated in 1968, redefined the St....