Tapeworm Railroad
The Tapeworm Railroad was a railway line planned by Congressman Thaddeus Stevens and nicknamed by opponents ridiculing a lengthy serpentine section around the Green Ridge of South Mountain after an orator compared the path to a tapeworm depiction on a product's packaging. Switchbacks were planned on the west slope at Hughs Forge along the E Br Antietam Creek and on the east slope at Stevens' 1822 Maria Furnace along Toms Creek (Monocacy River), with three east slope tunnels through spurs of Jacks Mountain.
In 1836, Herman Haupt had surveyed the "road from Gettysburg across South Mountain to the Potomac" and in 1838, the rail "bed" was "graded for a number of miles, never got further than Monterey", and included the following :
- single-arch roadway bridge over Toms Creek west of Iron Springs, Pennsylvania
- multi-arch bridge
- viaduct at Virginia Mills
- deep cut near Marsh Creek
- elevated railbed on banks of Willoughby Run
- McPherson Ridge railway cut, site of the 1863 Battle of Gettysburg military engagements on McPherson Ridge
- Seminary Ridge railway cut
The Tapeworm Railroad right-of-way was later used by the Susquehanna, Gettysburg and Potomac Railway and its successor, the Baltimore and Harrisburg Railway to build a line from Gettysburg west to Highfield, Maryland.