The Eads Bridge is a combined road and railway bridge over the Mississippi River connecting the cities of St. Louis, Missouri, and East St. Louis, Illinois. It is located on the St. Louis riverfront between Laclede's Landing to the north, and the grounds of the Gateway Arch to the south. The bridge is named for its designer and builder, James Buchanan Eads. Work on the bridge began in 1867, and it was completed in 1874. The Eads Bridge was the first bridge across the Mississippi south of the Missouri River. Earlier bridges were located north of the Missouri, where the Mississippi is smaller. None of the earlier bridges survive, which means that the Eads Bridge is also the oldest bridge on the river.

St. Louis is an independent city in the U.S. state of Missouri. It is located near the confluence of the Mississippi and the Missouri rivers. In 2020, the city proper had a population of 301,578, while its bi-state metropolitan area, which extends into Illinois, had an estimated population of over 2.8 million. It is the largest metropolitan area in Missouri and the second largest in Illinois. The city's combined statistical area (CSA) is the 20th largest in the United States.