What group of people operated the underground railroad

Harriet Tubman is by far the most notable person to operate it but also had many notable participants, including John Fairfield in Ohio, the son of a slaveholding family, who made many daring rescues, Levi Coffin, a Quaker who assisted more than 3,000 slaves, and Harriet Tubman, who made 19 trips into the South and escorted over 300 slaves to freedom. People where known as conducters and lead people to safe houses, and "station" where "station Masters" looked after them