Harriet Tubman

Tubman left her family in her early 20s to escape to Philadelphia, then a hotbed of abolitionism. There she became the first and only woman, fugitive slave, and black to work as a conductor on the Underground Railroad. So successful was she in spiriting away slaves that the state of Maryland put a $40,000 bounty on her head. Within a year of starting her work, fellow slaves and Northerners began referring to Tubman as "Moses" because of how many people she had freed.