Harriet Tubman was a big part of the Underground Railroad, she helped over 300 slaves escape. Harriet made over 19 trips back down to help free more slaves. There was a 40,000 dollar reward for her capture at one point because of what she was doing.
Slaves would escape alone or in groups during the night and hide during the day at "stations." They planned a route with the help of others or conductors. They would run through fields or woods were they were less likely to be caught. For those who were caught were beaten severely and sometimes even killed.
Conductors along the Underground Railroad allowed escaped slaves trying to reach freedom to hide in their sheds, attics, or basements during the day. Their houses would contain secret trap doors and holes in walls where the slaves could hide during the day. Slaves would follow the North Star at night to find their way.