In 1982, law changes allowed Conrail to shed its commuter rail operations in order to focus on its more profitable freight operations.
On January 1, 1983, public operators (including Metro-North Railroad, New Jersey Transit, and SEPTA Regional Rail) took over Conrail commuter rail systems in the Northeast.
C., to Martinsburg, West Virginia, over the CSXT Metropolitan and Cumberland Subdivisions (both former Baltimore and Ohio Railroad (B&O) lines), and the Amtrak Washington Terminal District.
The Brunswick Line service also includes a 14 miles (23 km) branch serving Frederick, which diverges from the Metropolitan Subdivision at East Rocks (just east of Point of Rocks) before traveling over the CSXT Old Main Line and the MDOT Frederick Branch.
Prior to 1978, most ex-PRR Baltimore-Washington service was operated by aging MP54 electric multiple units, most dating back to the line's 1933 electrification.
MARC is administered by the Maryland Transit Administration (MTA), a Maryland Department of Transportation (MDOT) agency, and is operated under contract by Bombardier Transportation Services USA Corporation (BTS) and Amtrak over tracks owned by CSX Transportation (CSXT) and Amtrak.
Local service north of Baltimore on the PRR ended around 1964.
Passenger rail service declined from a variety of factors (particularly the advent of the automobile) in the mid 20th century, even as commuting from suburban locations to urban business districts remained common.
On March 1, 1974, the Maryland Department of Transportation (MDOT) began a 50% subsidy of the B&O's Washington-Brunswick and Washington-Baltimore service - the first state-sponsored commuter rail service to Washington.
Later in the decade, West Virginia began to fund the B&O shuttles between Brunswick and Martinsburg; the shuttles were soon incorporated as extensions of Brunswick service in order to secure Urban Mass Transportation Administration subsidies.