The Baltimore Terminal Subdivision is a
railroad
Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...
line owned and operated by
CSX Transportation
CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. The railroad operates approximately 21,000 route miles () of track. ...
in the
U.S. state of
Maryland
Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; ...
. The line runs from
Baltimore
Baltimore ( , locally: or ) is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic (United States), Mid-Atlantic, and List of United States cities by popula ...
to
Halethorpe along the original
Baltimore and Ohio Railroad
The Baltimore and Ohio Railroad was the first common carrier railroad and the oldest railroad in the United States, with its first section opening in 1830. Merchants from Baltimore, which had benefited to some extent from the construction of ...
(B&O) line, one of the oldest rail lines in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
and the first
passenger railroad
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often kno ...
line. At its east (north) end, it connects with the
Philadelphia Subdivision; its west (south) end has a junction with the
Capital Subdivision and the
Old Main Line Subdivision
The Old Main Line Subdivision is a railroad line owned and operated by CSX Transportation in the U.S. state of Maryland. The line runs from Relay (outside Baltimore) west to Point of Rocks, and was once the main line of the Baltimore and Ohio Ra ...
.
History
Mount Clare to points south and west
The B&O began construction in 1828. The original terminal was located in Baltimore at Pratt and Poppleton Streets. This location, initially a temporary wooden shed, became known as the
Mount Clare Station. The
Mount Clare Shops, the first railroad manufacturing facility in the U.S., was also built in this area. The rail line exited the city in a southwesterly direction. The company encountered varied terrain that required several large
cut and fill earthmoving operations. The B&O built the
Carrollton Viaduct, the first stone
masonry
Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term ''masonry'' can also refer to the units themselves. The common materials of masonry construction are bricks, building ...
bridge built for a U.S. railroad, during this project. The company provided an inaugural ride on the line from Pratt Street to the viaduct on New Year's Day 1830. The bridge, a
National Historic Landmark
A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places listed ...
, is still used by CSX today.
[The Carrollton Viaduct is located on the present-day Mount Clare Branch, about 1 mile (1.6 km) south of the Carroll junction on the main line. The B&O rebuilt the main line tracks in the 1870s.] Construction of the
tracks continued southward to the
Patapsco River
The Patapsco River mainstem is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed April 1, 2011 river in central Maryland that flows into the Chesapeake Bay. The river's tidal port ...
near Halethorpe, and then turned west following the river. Today Halethorpe is the southern terminus of the Baltimore Terminal Subdivision.
The railroad offered the first regular
passenger train
A passenger train is a train used to transport people along a railroad line. These trains may consist of unpowered passenger railroad cars (also known as coaches or carriages) hauled by one or more locomotives, or may be self-propelled; self p ...
service in the U.S. in May 1830, from Baltimore to Ellicott's Mills (now called
Ellicott City) along the Patapsco. The first permanent
train station
A train station, railway station, railroad station or depot is a railway facility where trains stop to load or unload passengers, freight or both. It generally consists of at least one platform, one track and a station building providing ...
, the
Ellicott City Station, was completed in 1831.

Also in 1831, the B&O built a junction, known as
Relay
A relay
Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts
An automotive-style miniature relay with the dust cover taken off
A relay is an electrically operated swit ...
, just north of the river near Halethorpe and began construction of the
Washington Branch
Washington commonly refers to:
* Washington (state), United States
* Washington, D.C., the capital of the United States
** A metonym for the federal government of the United States
** Washington metropolitan area, the metropolitan area centered o ...
south toward
Washington, D.C. (This branch was later named the Capital Subdivision.) The section of the line proceeding west from Relay, along the Patapsco, eventually became known as the Old Main Line.
The B&O built a
branch line
A branch line is a phrase used in railway terminology to denote a secondary railway line which branches off a more important through route, usually a main line. A very short branch line may be called a spur line.
Industrial spur
An industr ...
to
Locust Point, on the Baltimore harbor, during 1848-49. The branch had a
rail yard
A rail yard, railway yard, railroad yard (US) or simply yard, is a series of tracks in a rail network for storing, sorting, or loading and unloading rail vehicles and locomotives. Yards have many tracks in parallel for keeping rolling stock or ...
and terminal that was used for shipping
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as stratum, rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen ...
and bulk minerals, and later for
grain
A grain is a small, hard, dry fruit ( caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legu ...
and merchandise. A permanent station at Mount Clare was completed c. 1851. The railroad opened the larger
Camden Station nearby in 1857, and expanded it in 1865. In 1875 new
roundhouses were built at Bailey's (Ostend Street, near the site of the present-day
M&T Bank Stadium
M&T Bank Stadium is a multi-purpose football stadium located in Baltimore, Maryland. It is the home of the Baltimore Ravens of the National Football League (NFL). The stadium is immediately adjacent to Oriole Park at Camden Yards, the home of th ...
) and Riverside Yard on Locust Point. Another branch line and a larger shipping terminal at
Curtis Bay was opened in 1884. Subsequently all coal traffic was routed to the new terminal.
The B&O built two larger roundhouses at Riverside in 1907 (totaling 50 stalls) and no longer used the Bailey's facilities for
locomotive operations.
Baltimore to Philadelphia

The B&O's initial route from Baltimore to
Philadelphia
Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Sinc ...
was on the
Philadelphia, Wilmington and Baltimore Railroad
The Philadelphia, Wilmington and Baltimore Railroad (PW&B) was an American railroad that operated independently from 1836 to 1881.
It was formed in 1836 by the merger of four state-chartered railroads in three Middle Atlantic states to create a ...
. The B&O operated a
car float
A railroad car float or rail barge is a specialised form of lighter with railway tracks mounted on its deck used to move rolling stock across water obstacles, or to locations they could not otherwise go. An unpowered barge, it is towed by a ...
across the Baltimore harbor to bring trains from Philadelphia to connections at Locust Point and to the south and west. By the early 1880s this line was controlled by the
Pennsylvania Railroad
The Pennsylvania Railroad (reporting mark PRR), legal name The Pennsylvania Railroad Company also known as the "Pennsy", was an American Class I railroad that was established in 1846 and headquartered in Philadelphia, Pennsylvania. It was named ...
, which proceeded to deny access to the B&O. The B&O then built the Philadelphia Branch (known formally as the
Baltimore and Philadelphia Railroad
The Baltimore and Philadelphia Railroad was a railroad line built by the Baltimore and Ohio Railroad (B&O) from Philadelphia, Pennsylvania, to the Maryland-Delaware state line, where it connected with the B&O's Philadelphia Branch to reach Baltimor ...
). To move trains more efficiently around the city it also built the
Baltimore Belt Line and the Howard Street Tunnel during 1891 to 1895, at considerable expense. The car float operation was shut down after the new facilities opened.
The
Mount Royal Station, along the Belt Line, opened in 1896. This became the second of two Baltimore stops for the
Royal Blue
Royal blue is a deep and vivid shade of blue. It is said to have been created by clothiers in Rode, Somerset, a consortium of whom won a competition to make a dress for Queen Charlotte, consort of King George III.
Brightness
The ''Oxford ...
passenger train, which began service in 1890 between Washington and
New York City
New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the U ...
. (The other stop was Camden Station.) Passenger traffic declined significantly after
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
and the B&O closed the Mount Royal station in 1961.

The junction of the Philadelphia Branch and the Belt Line, in east Baltimore, is the northern terminus of the Baltimore Terminal Subdivision.
CSX acquisition
CSX completed formal acquisition of the B&O in 1987.
Current operations
The Baltimore Terminal Subdivision continues to support both
freight
Cargo consists of bulk goods conveyed by water, air, or land. In economics, freight is cargo that is transported at a freight rate for commercial gain. ''Cargo'' was originally a shipload but now covers all types of freight, including trans ...
and passenger train operations.
Local
commuter passenger trains are operated on the line by the state-run
MARC Train
MARC (Maryland Area Rail Commuter) is a commuter rail system in the Baltimore–Washington metropolitan area. MARC is administered by the Maryland Transit Administration (MTA) and operated under contract by Alstom and Amtrak on track owned by ...
service. The MARC
Camden Line operates between Camden Station and Washington's
Union Station.
See also
*
Howard Street Tunnel fire
The Howard Street Tunnel fire (also known as the Baltimore Freight Rail Crash) was a 60-car CSX Transportation freight train derailment that occurred in the Howard Street Tunnel, a freight through-route tunnel under Howard Street in Baltimo ...
(2001)
*
List of CSX Transportation lines
CSX Transportation owns and operates a vast network of rail lines in the United States east of the Mississippi River. In addition to the major systems which merged to form CSX – the Baltimore and Ohio Railroad, Chesapeake and Ohio Railway, Lo ...
Notes
References
*
*
External links
{{commons category
Baltimore and Maryland Railfan Maps and Guides– Maps of Baltimore Terminal Sub, Yards & Connecting Lines
- Photos and track diagrams
Baltimore and Ohio Railroad lines
CSX Transportation lines
Rail infrastructure in Maryland