Florence was a location where travelers seemed to want to cross the Illinois river in the 1800s. After a ferry was organized, the line waiting to cross the river was often several hours long. The bridge was installed as part of the US highway system. It carried US-36 until the new Valley City Eagle Bridges were built as part of the I-72 project in 1988. US-36 is now multiplexed on I-72 in western Illinois. Given that I-72 is only a few miles to the north, the Florence bridge is very lightly used.

The bridge consists of 4 Parker style through truss spans, the main lift span, and then 4 more Parker style through truss spans. There is a lengthy causeway on the east end of the crossing, and a very short fill on the west end.

The Florence bridge was refurbished in 1981, and refurbished again in 2004. In the 2004 project, the deck was replaced, the bridge was sandblasted and painted, the lift cables were replaced, a new operators house was built, and electrical work was performed.

During the Civil War, the 99th Illinois Infantry was composed of men from the area around Florence, most of whom lived in Pike County. They left for Saint Louis to join the war August 23, 1862, from a spot near the bridge. A monument marks the spot where they loaded onto a riverboat. The unit was under fire 62 days before the war ended.

Update—the Florence Bridge was closed on June 28, 2012, when a routine inspection revealed a structural issue at the top of one of the lift towers. This caused one set of large pulleys at the top of the bridge to shift laterally. If the bridge were to remain in operation, additional damage would occur that would be much more difficult to repair. The bridge is expected to be closed at least 9 months while a repair strategy is developed. In the mean time, the lift span has been left in the open position to allow river navigation traffic to pass under the structure.