It was a clandestine operation that began during the colonial period, later became part of organized abolitionist activity in the 19th century, and reached its peak in the period 1830 - 1865. The story of the Underground Railroad is one of individual sacrifice and heroism in the efforts of enslaved people to reach freedom from bondage. In 1990 Congress directed the National Park Service to study how to best interpret and commemorate the Underground Railroad, emphasizing the approximate routes taken by slaves escaping to freedom before the Civil War. This study was completed in cooperation with an advisory committee representing experts in historic preservation, African American history, United States history, and members of the general public with special interest and experience in the Underground Railroad. A few elements of the story are represented in existing NPS units and other sites, but many important resource types are not adequately represented and protected.
Many sites remain that meet established criteria for designation as national historic landmarks.
Many sites are in imminent danger of being lost or destroyed. There is a tremendous amount of interest in the subject, but little organized coordination and communication among interested individuals and organizations. Some sites have very high potential for preservation and visitor use. No single site or route completely reflects and characterizes the Underground Railroad. The story and resources involve networks and regions rather than individual sites and trails.