Harriet married John Tubman, a free Black, at the late age of 24. At age 29, upon hearing rumors that she and her brothers were to be sent south as part of a chain gang, she escaped to freedom in Pennsylvania, settling in Philadelphia, a haven for runaways. She began working as a domestic, rigidly saving her money, and studying the secretive "underground railroad," a support system for shepherding runaways from the south to free territories. In 1850, Harriet Tubman made the first of some 19 journeys to assist an estimated 300 other enslaved Blacks to escape chattel slavery. In 1851 she separated from John Tubman after discovering that he had taken another bride. Her success at liberating her people was so renowned that the Blacks called her "Moses" and white enslavers placed a $40,000 bounty on her head, an unbelievable sum of money at that time. Despite great opposition, Harriet proudly told one archivist, "I never ran my train off the track and I never lost a passenger."

During her life she worked with the famous abolitionist John Brown, served as a nurse, scout and spy for the Union Army during America's Civil War. One raid, in June 1863, the first military mission in U.S. history lead by a woman, succeeded in liberating 765 blacks from plantations near Beaufort, South Carolina. Despite her notoriety as a she-roe of the Civil War and the Underground Railroad, she struggle with poverty throughout the subsequent 5 decades of her life. At age 50 she married a man half her age, Nelson Davis, who died in 1888. Harriet continued to have a life full of activity, notoriety and struggles for human rights. She lived to the ripe old age of 93 years, passing on March 10, 1913.