I, too recommend Eleanor Burns' book. You may even be able to borrow it from your local library. I live in a part of Virginia that was occupied by large numbers of Quakers. Quakers were very, very supportive of slaves who were running away and heading north and they often put themselves and their families in danger by hiding runaway slaves and/or hanging quilts out their windows or over their fences to help point slaves toward the next portion of their journey. It's a wonderful story and it's amazing to live in an area where so much of it took place.