Edmonds' career took a turn during the war when a Union spy in Richmond, Virginia was discovered and put before a firing squad, and her friend James Vesey was killed in an ambush. She took advantage of the open spot and the opportunity to avenge her friend's death. She applied for the position in the guise of Franklin Thompson. There is no proof in her military records that she actually served as a spy, but she wrote extensively about her experiences in disguise during the war.