Excerpt:
Begun in 1867 and completed in 1874, the Eads Bridge was named after its designer, James Buchanan Eads. It was the first bridge to span the Mississippi at St. Louis, the first bridge to make significant of steel, and one of the first bridges in the U.S. to make use of pneumatic caissons (the caissons sunk for the bridge are still among the deepest ever). It was also the first bridge to be built entirely using cantilever construction methods, avoiding the need for falsework, and the first bridge designed so that any part could be removed for repair or replacement. The bridge is now a National Historic Landmark.
Annotation:
Scope and content of the collection of original drawings of the Eads Bridge. Washington University.