This line was one of the original railroad routes in the United States. According to printed narratives (available at the New Freedom, PA museum/station), the line was chartered in 1828 as the Baltimore & Susquehanna. Construction started in 1829, and it reached York, PA in 1838. In 1855 the Northern Central was created, when the Baltimore & Susquehanna and other local lines were merged. By the 1860s the line was controlled by the Pennsylvania RR, and it merged into the PRR in 1914. Regardless, the Northern Central name continued to be used.
The line was traveled by President Lincoln in 1863 on his way to delivering the Gettysburg Address. This route also carried the funeral trains for four presidents: Harrison (1841), Taylor (1850), Lincoln (1865) and Harding (1923).
The line was eventually upgraded and double tracked, however it was saddled with a winding route with grades. Freight trains eventually bypassed it for the parallel PRR route along the Susquehanna River further east. Over the years traffic declined, the line reverted to single track, and passenger service ended on April 30, 1971 upon the advent of Amtrak. The line was damaged by Hurricane Agnes in 1972 and was closed to freight traffic (by then Penn Central) shortly after that.
The states of Pennsylvania and Maryland eventually created a rail trail along the route, including the "still active" York to New Freedom, PA segment. South of New Freedom to the Pennsylvania state line, a single track is still in place but it is severed from the rail network and at most grade crossings. The trail along the route is well marked, and local highways have "NCR Trail" signs posted to direct travelers to the route. The New Freedom, PA and Monkton, MD stations have been rebuilt and are in great shape. A few steel and cement bridges remain, along with an occasional relay box, but most other railroad hardware has been removed. The south end of the trail is at Ashland, MD. Further south of that location, the line into Baltimore has been rebuilt as part of the light rail transit system, and Norfolk Southern uses it during off hours.
Heading south from New Freedom, PA, the line passed through the following settlements and towns in MD: Freeland, Bentley Springs, Walker, Parkton, Graystones, White Hall, Blue Mont, Monkton, Corbett, Glencoe, Sparks, Phoenix, Ashland, and Cockeysville.