Harriet Tubman ( born Araminta Ross ; c. 1820 or 1821 â `` March 10 , 1913 ) was an African-American abolitionist , humanitarian , and Union spy during the American Civil War . Harriet Tubman ( born Araminta Ross ; c. March 1822 â `` March 10 , 1913 ) was an African-American abolitionist , humanitarian , and Union spy during the American Civil War .