The individual who led the underground railroad to assist runaway slaves in the 19th century United States was Harriet Tubman. As a former enslaved person herself, Tubman became a prominent conductor on the Underground Railroad, risking her life to guide others to freedom in the Northern states and Canada. Over her lifetime, she successfully led many trips, earning her the nickname "Moses of her people." Tubman’s courageous efforts highlighted the injustices of slavery and contributed significantly to the abolitionist movement, making her an enduring figure in American history.