Ruins of R.R. bridge across Tennessee River, at Bridgeport, Tenn.? (i.e. Alabama) and pontoon bridge in course of construction
Caption provided by Minnesota Historical Society from the NPS Civil War Series: The Battles of Chickamauga: The Confederates destroyed the railroad bridge over the Tennessee River at Bridgeport, Alabama, in their retreat from middle Tennessee. Major General Philip H. Sheridan's Union Division constructed the trestle and pontoon bridge in late August 1863 as part of Rosecrans's advance prior to Chickamauga. An engineering weakness caused the trestle structure to collapse twice during the Federal crossings. In this photo, the temporary bridge is under construction for the first time.
http://www.loc.gov/pictures/item/2012649979/
View this photo at lcweb2.loc.gov
BH Photo #259200