Complex sentence: Garrett was also a friend and benefactor to the great Underground Railroad Conductor, Harriet Tubman, who passed through his station many times, during which he frequently provided her with money and shoes to continue her missions of conducting runaways from slavery to freedom.
Split into simpler sentences: Garrett was also a friend and benefactor to the great Underground Railroad Conductor Harriet Tubman. She passed through his station many times, during which he frequently provided her with money and shoes to continue her missions of conducting runaways from slavery to freedom.