Throughout American history, bridges have been sources of both pride and controversy. The country’s early westward expansion followed the paths of rivers, but the frontier truly began to open up only with the arrival of railroads—and railroads required bridges. Many of those bridges were poorly designed and unreliable. At one point in the 19th century, one of every five collapsed within a few years of construction. They faced political opposition as well; rail traffic threatened the riverboat industry and cities such as St. Louis, which boomed during the steamboat era.
During much of the 19th century, St. Louis was cut off from the eastern side of the country, since the Mississippi River was too wide and the current too strong to allow any bridge to be constructed nearby. But that all changed when an engineer named James Eads accomplished the impossible, designing and building what at that time was the longest-span bridge in the world.
“Cast-iron was the most commonly used metal before the development of steel,” says Fouad H. Fouad, Ph.D., chair of the UAB Department of Civil, Construction, and Environmental Engineering. “But cast-iron is not good for building bridges, because it is very brittle.” To span the Mississippi, Eads needed something more durable, but with the same strength. He found what he was looking for with the development of steel; his bridge used a series of steel arches to support three spans of more than 500 feet, including a center span of 520 feet—a distance that had previously been deemed impossible. Eads Bridge, which is still in use today, was an engineering marvel—it was also considered a piece of modern art, serving as the inspiration for the St. Louis Arch.
— Grant Martin