Johnstown PA near the Flight 93 Memorial has a very interesting history. A disastrous flood caused by human error swept through the city in 1889. There's a National Park Memorial at the dam site -
http://www.nps.gov/jofl/index.htm Stop in the city too and ride the incline -
http://www.inclinedplane.org/ And visit the other museums -
http://www.jaha.org/FloodMuseum/oklahoma.html http://www.jaha.org/DiscoveryCenter/virtualtour.html As you work your way south to DC don't miss Harpers Ferry NP -
http://www.nps.gov/hafe/index.htm
