The Eads Bridge over the Mississippi River was the first arched steel truss bridge in the world. When it was first proposed the idea was highly unpopular as thought to be impossible to build. Completed in 1874 it was the first bridge to be built using cantilever support methods exclusively, and one of the first to make use of pneumatic caissons. The Eads Bridge caissons, still among the deepest ever sunk, were responsible for one of the first major outbreaks of “caisson disease” (also known as “the bends” or decompression sickness). Fifteen workers died, two other workers were permanently disabled, and 77 were severely afflicted. The Eads Bridge combined road and railway over the Mississippi River at St. Louis, connecting St. Louis and East St. Louis, Illinois.
The bridge is named for its designer and builder, James B. Eads. When completed in 1874, the Eads Bridge was the longest arch bridge in the world, with an overall length of 6,442 feet (1,964 m). The ribbed steel arch spans were considered daring, as was the use of steel as a primary structural material: it was the first such use of true steel in a major bridge project.
On 14 June 1874, John Robinson led a “test elephant” on a stroll across the new Eads Bridge to prove it was safe. A big crowd cheered as the elephant from a traveling circus lumbered towards Illinois. It was believed that elephants had instincts that would keep them from setting foot on unsafe structures. Two weeks later, Eads sent 14 locomotives back and forth across the bridge at one time. The opening day celebration on July 4, 1874 featured a parade that stretched fifteen miles through the streets of St. Louis.
The Eads Bridge, which became an iconic image of the city of St. Louis, from the time of its erection until 1965 when the Gateway Arch was constructed, is still in use. The bridge crosses the St. Louis riverfront between Laclede’s Landing, to the north, and the grounds of the Gateway Arch, to the south. Today the road deck has been restored, allowing vehicular and pedestrian traffic to cross the river. The St. Louis MetroLink light rail line has used the rail deck since 1993.