Harriet Tubman
Although she is known as an Underground Railroad icon, Harriet Tubman also worked on a major Union military operation. She became the first black woman to lead a military expedition in 1863 at the Combahee River, now known as the Combahee River Raid.
Tubman started her work in the military as a nurse and a cook but later became a spy, providing secrets and intelligence to the Union Soldier and then an armed scout.