The James B. Eads Bridge received special recognition for its outstanding historical significance and for 100 years of service to the nation. When built, it was the first construction alloy steel bridge and the largest bridge of any type. It opened to traffic in 1874. Eads Bridge was later designated a Registered National Historic Landmark under the Historic Sites Act of August 21, 1935, as a site possessing exceptional value in commemorating and illustrating the history of the United States.