The history of liberty makes clear that the people who gain their liberty are generally those who fight long and hard and smart for it. This is because individuals who hold power never willingly give it up.

Few freedom fighters were more tenacious than petite Harriet Tubman, the African-American slave-turned-abolitionist who died March 10, 1913 when she was about 92. She escaped to freedom, then was reported to have gone back into the Confederacy 19 times, risking capture as she “conducted” some 300 slaves to freedom. Although she was illiterate, she came to know the Mid-Atlantic and Northeast region so well that she could take confusing, zig-zag routes, making it hard for pursuers to figure out where they might be able to intercept her. She was tough, too, enduring brutal conditions and always packing a pistol.

She was born to parents who were slaves, and she grew up on a Dorchester, Md., plantation, along with seven siblings. She was beaten repeatedly by her masters. A deep scar on her forehead marked the spot where she was hit hard enough to cause periodic blackouts for the rest of her life. On one occasion, when she was working near a road, a sympathetic white woman stopped and offered to help in any way she could. Tubman noted that.

Her owner subsequently sold two of her sisters, and they were probably condemned to a Deep South chain gang. Tubman never saw them again. This convinced her that she must try to escape. In September 1849, after everyone was asleep, Tubman fled and found her way to the house of the friendly woman. The woman provided food and directions to others who would help on the Underground Railroad, the informal network of volunteers that was organized spontaneously after the American Revolutionary War. The Underground Railroad defied laws in the North as well as the South. At night, away from roads that were patrolled, Tubman tried to follow the North Star and make her way hundreds of miles through dense forests, feeling her way one tree at a time.

Tubman reached Philadelphia in December. She recalled, “I looked at my hands to see if I was the same person now that I was free. There was such a glory over everything. The sun came like gold through the trees and over the field, and I felt like I was in heaven.”

She found a job cooking and cleaning up in a hotel kitchen. She did that for about a year, saving some money. She also talked with people at Philadelphia’s Vigilance Committee that helped runaway slaves. She heard that her sister — a slave with children — was going to be sold away from her husband, who was a free black. Tubman decided she would return to Maryland and guide them to freedom. That was her start as a “conductor” on the Underground Railroad.

Then in 1850, the Fugitive Slave Act empowered Southern slave hunters to capture alleged runaways without a jury trial, and Tubman began conducting slaves hundreds of miles farther north — across the Canadian border. She knew the abolitionist orator Frederick Douglass, whose three-story house in Rochester, N.Y., was the last stop for many slaves on the Underground Railroad before they boarded a steamer across Lake Ontario.

By the time Tubman began her epic mission, the Underground Railroad had expanded dramatically from its humble origins in the 1780s. Historian John Hope Franklin cited estimates that at the peak as many as 3,200 people participated, helping runaway slaves in one way or another — donating money, providing food, hiding slaves in haystacks, taking them across rivers, and so on. Tubman was rated the outstanding conductor, personally accompanying perhaps more runaway slaves than anyone else. When she appeared at a plantation, secretly evaluating prospective “passengers” for her next trip, word spread fast in the slave quarters — “Moses is here!” Later, up North, abolitionist records credited her new arrivals to “Moses.”

During the Civil War, Tubman served as a scout and spy. For example, she was the scout for the Combahee River Raid (1863) that liberated some 750 slaves in South Carolina.

Tubman’s amazing achievements testified to the importance of self-help for blacks, as well as everyone else. The more slaves she conducted to freedom, the faster word spread that it really was possible to be free, and the more slaves took initiative to free themselves. Ultimately, the fatal weakness of the slave system was the determination of multitudes to take matters into their own hands.