R. Conrad Stein & Charlotte Taylor 
Underground Railroad [PDF ebook] 

The Underground Railroad was a complex network of secret routes, safe houses, and courageous men and women, both black and white, who helped slaves escape to free states and to Canada. "Conductors, " such as Harriet Tubman, risked recapture in the South guiding slaves to freedom. Readers explore the formation of this extremely effective anti-slavery escape network and the people who made it work.