To this day the Medal of Honor, the highest honor that can be given to recognize U.S. military service, has only been awarded to one woman. That woman was Dr. Mary Edwards Walker. 

A surgeon who earned her medical degree in 1855, Dr. Walker volunteered with the Union Army during the Civil War, despite the fact that women physicians were considered unfit for military service at the time. She frequently crossed battle lines to treat civilians, and this led to her capture by Confederate troops in 1864. She was held as a prisoner of war until her release in a prisoner exchange four months later. 

After the war, Dr. Walker became a writer, lecturer and advocate in support of women's rights. She was arrested many times for wearing men's clothes, but never stopped insisting on her right to wear the clothing she felt was appropriate. 

Dr. Walker tried to vote in 1871, but was turned away. She became a leading member of the early suffrage movement, arguing that women already had a constitutional right to vote. Dr. Walker never stopped pushing for women's rights. 

She died in 1919, one year before the 19th Amendment guaranteed women the right to vote. She was buried in her home town of Oswego, New York, wearing a black suit instead of a dress.