The Key Bridge was not the original connector between Georgetown and Virginia. Prior to that construction in the 1920s, there were two iterations of the Aqueduct Bridge, both of which can be seen above. Both versions used the same piers, but the initial wooden bridge, designed by Major William Turnbull was just meant to carry canal boats. It did just that, but it also served as a Civil War roadway, which was its function at the time of the first photo. The second iteration of the bridge looked visibly different, but even that one suffered from deterioration and was only used between 1889 and 1918.
· Aqueduct Bridge (Potomac River) [Wikipedia]
· All Looking Back Coverage [CDC]