CSS Atlanta after capture by Union forces. CSS Atlanta was originally converted from a British-built blockade runner named Fingal by the Confederacy after she made one run to Savannah, Georgia. After several failed attempts to attack Union blockaders, the ship was captured by two Union monitors in 1863 when she ran aground. Atlanta was repaired, and rearmed, serving in the Union Navy for the rest of the war. She spent most of her time deployed on the James River supporting Union forces there.