Thebes was a choke point for rail traffic coming south out of Chicago. The Cotton Belt operated a ferry service that took entire trains across the river. A second ferry was opened, but still was not able to keep up with traffic demands. A group of five local railroads pooled their efforts to build a permanent bridge.

The Thebes rail bridge was designed by famous bridge builder Ralph Modjeski. They built a very strong bridge since this bridge was to carry two tracks, which could see two trains cross the river at once. In addition, they envisioned auto traffic becoming more popular, and they built in provisions to add a car deck to the bridge someday in the future. As it turns out, the auto deck was never added. Due this extra strength, the Thebes rail bridge is known as the strongest bridge over the Mississippi River.

The bridge abutments are made out of reinforced concrete. While that is common today, this is a very early example of the use of this material. Some considered it risky when it was built. It is still standing over 100 years later despite being in daily use carrying ever larger and heavier trains.

While the new bridge streamlined traffic, the trains now had no reason to stop at Thebes. As a result, the town more or less dried up and blew away. Today, it is little more than a camp ground, a few seasonal houses, a few older historic homes, and one very nasty public housing complex.