Cath Senker 
Who Travelled the Underground Railroad? [PDF ebook] 

How do we know about the American slaves who escaped using what is known as the Underground Railroad, and about the people that organized it? What were they escaping from, and what happened to them? This book shows how we know about the fugitives and their experiences from primary and other sources. It includes information on some historical detective work that has taken place, using documentary and archaeological evidence, that has enabled historians to piece together the fascinating story of the Underground Railroad.