Watch Online HD on HDtoday. The Underground Railroad was not really a railroad, nor was it always underground. It was an informal network of people and hiding places that helped slaves escape the American South. It extended from the South into the northern states, Canada, the western frontier, and even Cuba and the Caribbean. This documentary remembers the people, white and black, famous and almost-forgotten, who risked their fortunes and even their lives to resist the unjust institution of slavery.