From Bridge Hunter 1:
This bridge was built in 1931 at the location of an earlier bridge built in 1859 and modified in the 1870's. In 1941 the bridge had to be raised due to the creation of Kentucky Lake through controlled TVA flooding. In 1981 the vertical lift span was disassembled and floated down the Tennessee River on barges and reassembled at Bridgeport, Alabama. The bridge remains in service there today.I would have said they floated up the river because Bridgeport is upstream from Danville.
Search in ExploreKentuckyLake for "first railroad" to see an image of the 1861-1931 swing span. The picture below that image is a picture of the raising of the bridge.