While a member of the 53rd Ohio Volunteers during the Civil War, Dawes was wounded in the face at the Battle of Dallas in May 1864 during the Atlanta Campaign and was grossly disfigured as a result. A prolific writer of regimental and war histories after the conflict, Dawes was fitted with a prosthetic jaw with lower teeth and adopted a full beard to cover his wounds. Lithographers and publishers used his 1863 likeness for his publications.