This bridge is very interesting to cross when heading northbound. The bridge appears to be built with a step in the middle. That is, you go up a steep grade, then level off a bit, then head up a second steep grade. The grades do not appear anywhere as steep when you look at the bridge from the side as they do when you drive over the bridge.
Despite this two step feature, the main bridge is symmetrical on each side of the river. The ground on the north side is higher and the river flats on the south end of the bridge. As a result, the south end of the bridge required a ramp to be built to get up to the same level where the north end of the bridge starts at, resulting in the extra grade and the step on the south end of the structure.
Work was started on this bridge in 1929. Due to the depression, money for the bridge ran out. The State of Illinois eventually stepped in and finished the bridge in 1933. When built, the bridge was billed as the longest bridge in the world, however, despite being a healthy sized bridge, it was far from the longest. Just after it opened, the American Institute of Steel Construction awarded this bridge the prize of being the most beautiful deck truss bridge in the United States.