Harriet was a slave, until she would take no more. Harriet was hired out to toil in the fields of her owner's neighboring farmer's plantations in Maryland. In 1849, when more slaves were being sold to the south Harriet decided to run away to the north. At that time slaves were considered the property of their owners. Trying to run away was a crime against the law. So was helping a slave to run away.
When darkness fell, Harriet set out. Following the North Star, she headed for Pennsylvania (a free state). Traveling only at night and mostly on foot, Harriet made the 90-mile journey to freedom.
She took a job in Philadelphia washing dishes. She needed money to go back to Maryland and lead others to their freedom. In all, Harriet made 19 trips, guiding her relatives and others out of captivity. Not one was captured and returned.
Slave owners often offered rewards for capturing slaves. Still, Harriet made one dangerous trip after another. To avoid being captured, Harriet would take different routes; she and her refugees sometimes wore disguises; they hid under wagons and in swamps; she drugged babies to keep their cries from drawing attention. As the pressure to capture slaves increased she guided them all the way to Canada for safety.
She knew people-both white and black-who offered a night's stay or food or shoes to the runaways. This network of safe havens was called the "Underground Railroad" because this help had to be kept secret. Otherwise these people would be arrested.
When the Civil War broke out, Union officials asked Harriet for help. She got information about the Confederate army from the blacks still in the South. She guided the Union army through unfamiliar territory. She cared for the wounded and sick in the hospital. Harriet received some modest pay for her work, as a spy and nurse. She also received a widow's pension and one for her nursing work in later life.
Back at her home in Auburn, New York, Harriet struggled to care for her aging parents and keep her home. Through her tremendous hard work and help of her loving and devoted family she was able to keep her house. But despite her own troubles, Harriet devoted herself to her "last work"-providing a home for aging and disabled black people.
There is a lot of new primary research on Harriet Tubman which can be found in two new books "Bound for the Promised Land" by Kate Clifford Larson and "Harriet Tubman, The Life and Life Stories" by Jean Humez.