Harriet Tubman (c. 1822 - 1913) was a conductor on the Underground Railroad, a secret network of routes and safe houses that guided black slaves from the American South to freedom in the North and into Canada. Born a slave herself, Tubman contributed to the northern effort in the American Civil War by serving as a Union Spy. Later in life and up until her death in 1913, Tubman was a staunch humanitarian and advocate for women's suffrage.
"I was the conductor of the Underground Railroad for eight years, and I can say what most conductors can't say — I never ran my train off the track and I never lost a passenger."
-Harriet Tubman, As quoted in Women's Words : The Columbia Book of Quotations by Women (1996) by Mary Biggs, p. 2 (h/t Wikiquote)