Sarah Edmonds was born in Canada in 1841 but faced abuse from her father, so she fled to the United States in 1857 under the alias Franklin Thompson disguised as a man. During the Civil War, Edmonds served for the Union Army while continuing the disguise, taking on roles like nurse, mail carrier, and spy. Edmonds suffered injuries during her service that lasted a lifetime. When she fell ill in 1863, Edmonds left the army without permission to avoid discovery as a woman and was charged with desertion, though this was later cleared by an act of Congress.