Mary Edwards was born in Oswego, New York, on 26th November, 1832. Determined to become a doctor, she graduated from Syracuse Medical College in 1855. She established a practice in Rome, New York, and married the physician, Albert Miller. The relationship was not successful and the couple separated in 1859.
Walker, a strong feminist, travelled to Washington on the outbreak of the American Civil War to offer her services to the Union Army. She worked as a volunteer nurse and was not sent to the front-line until September, 1863. Walker was appointed by General George Thomas as assistant surgeon in the Army of the Cumberland. The only woman doctor in the army, Walker served at Fredericksburg, Chickamauga and Atlanta.
Walker was also captured by the Confederate Army and spent four months in a Richmond prison (10th April, 1864 - 12th August, 1864). Released to tend the sick and wounded, Walker later claimed she used this opportunity to spy on the enemy. In 1865 she became the only woman in the American Civil War to win the Congressional Medal of Honor.
After the war Walker published two books, Hit (1871) and Unmasked (1878). She was also active in feminist organizations and was arrested several times for masquerading as a man. As well as campaigning for women's suffrage and for the Women's Christian Temperance Union, Walker gave lectures on the dangers of tobacco. Mary Edwards Walker died in Oswego, on 21st February, 1919. In 1917 Walker had her Congressional Medal of Honor revoked. President Jimmy Carter reinstated the ward in 1977.