The 70-mile stretch from Lancaster to Philadelphia is the first rail route to be recognized as part of the National Underground Railroad Network to Freedom. The program administered by the U.S. National Park Service recognizes historic places, facilities and educational and interpretive programs associated with the Underground Railroad. Philadelphia became a hub of the Underground Railroad because of its large free African-American community and renowned abolitionist movement, says historian Charles L. Blockson, founder and curator emeritus of the Charles L. Blockson Afro-American Collection at Temple University.