Introduction The Eads Bridge, spanning the Mississippi River and connecting St. Louis, Missouri, to East St. Louis, Illinois, is not only an engineering marvel but also a pivotal symbol of American ingenuity in the late 19th century. Completed in 1874, it was the first major bridge to be constructed using steel as its primary material and the first to employ pneumatic caissons for its piers. Designed by the self-taught engineer James Buchanan Eads, the bridge faced numerous challenges during its construction that tested the limits of contemporary engineering practices and human endurance.