At this location, Maj. R. G. Watson and his daughter Mary, both Confederate agents, lived and operated a direct mail and slave route between the North and the South during the entire Civil War. The unobstructed view from these cliffs made it an ideal location. Maj. Watson would meet the boat while Mary watched from an upstairs window and signaled if it was unsafe by placing a black flag in the window. Within a short distance of this point, John Wilkes Booth, Abraham Lincoln's assassin, crossed the Potomac in his historic flight.