Question: Where is the corporation that uses the Baltiore and Philadelphia Railroad today headquartered?

Context paragraphs:
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 Baltimore, Maryland.  It was built in the 1880s after the B&O lost access to its previous route to Philadelphia, the Philadelphia, Wilmington and Baltimore Railroad (PW&B).  The cost of building the new route, especially the Howard Street Tunnel on the connecting Baltimore Belt Line, led to the B&O's first bankruptcy.  Today, the line is used by CSX Transportation for freight trains.

Conestoga Creek Viaduct: The Conestoga Creek Viaduct spans the Conestoga River east of Lancaster, Pennsylvania.  The present structure, built in 1887-88, is a five-span, two-track stone arch railroad bridge.  The first crossing at this location was a 1412 ft series of 11 wooden Town lattice trusses constructed in 1829 for the Columbia and Philadelphia Railroad, which was purchased by the Pennsylvania Railroad (PRR) and incorporated into its main line in 1857.  PRR shortened the viaduct and replaced the remaining wooden trusses with iron Whipple trusses in 1863.  The 1887-88 stone arch replacement was originally intended to be four tracks wide, but only half of the superstructure width (two tracks) was constructed, leaving an unfinished spandrel wall on the southern face.  Tie rods were added in 1930 to brace the spandrel walls.

Glen Riddle (SEPTA station): Glen Riddle station was a commuter rail station on the SEPTA Regional Rail R3 West Chester Line, located underneath the South Pennell Road (PA-452) overpass in Middletown Twp, Pennsylvania.  Originally built by the West Chester and Philadelphia Railroad, it later served the Pennsylvania Railroad's West Chester Branch, which finally became SEPTA's R3 line.

Perth Amboy and Woodbridge Railroad: The Perth Amboy and Woodbridge Railroad was a railroad operated by the Pennsylvania Railroad.  The main line began along the Pennsy main at Rahway, New Jersey.  The line was only 6 miles long and was electrified in the year 1935.  The line ended at the now closed Essay Tower in South Amboy, New Jersey.  The rail line was double tracked and was used for both freight and passenger service.  At Essay it would become the New York and Long Branch Railroad which would run to Bay Head Junction.  At Essay traffic from the main or the South Amboy engine facility to the holding track outside the station.  Essay also controlled traffic on the Camden and Amboy Railroad today known as the Amboy Secondary Track.

Philadelphia Belt Line Railroad: The Philadelphia Belt Line Railroad owns a 2.66 mi long railroad line running along the Delaware River waterfront in Philadelphia, Pennsylvania.  It was created in 1889 to allow any Philadelphia railroad to access the waterfront.  The railroad, which does not operate any trains itself, is currently maintained by Conrail Shared Assets Operations and used by CSX Transportation and Norfolk Southern Railway.

CSX Transportation: CSX Transportation (reporting mark CSXT) is a Class I railroad in the United States.  The main subsidiary of the CSX Corporation, the railroad is headquartered in Jacksonville, Florida, and owns about 21,000 route miles (34,000 km).  CSX operates one of the three Class I railroads serving most of the East Coast, the other two being the Norfolk Southern Railway (NS) and Canadian Pacific Railway.  It also serves the Canadian provinces of Ontario and Quebec.  Together CSX and Norfolk Southern Railway have a duopoly over all east-west freight rail traffic east of the Mississippi River.  As of August 8, 2017, CSX's total public stock value was slightly over $41.5 billion.

West Chester and Philadelphia Railroad: The West Chester & Philadelphia Railroad (WC&P) operated in the greater Philadelphia area from 1848 to 1881.  It became the West Chester Branch of the Pennsylvania Railroad (PRR).  It has been operated as the Media/Elwyn Line on the SEPTA system since 1983.

Darlington station (SEPTA): Darlington station is a defunct commuter rail station on the SEPTA Regional Rail R3 West Chester Line, located at 612 Darlington Road in Chester Heights, Pennsylvania.  Originally built by the West Chester and Philadelphia Railroad, it later served the Pennsylvania Railroad's West Chester Branch, which finally became SEPTA's R3 line.

Wawa station: Wawa station is a defunct commuter rail station on the SEPTA Regional Rail R3 West Chester Line, located to U.S. Route 1 in Chester Heights, Pennsylvania.  Originally built by the West Chester and Philadelphia Railroad, it later served the Pennsylvania Railroad's West Chester Branch, which finally became SEPTA's R3 line.  The outer section of the line, including Wawa station, was closed in 1986.

Prescott Commercial Historic District: The Prescott Commercial Historic District encompasses the historic commercial core of Prescott, Arkansas, the county seat of Nevada County.  Prescott was laid out in 1873, after the railroad was built through the area that is now Nevada County, and the railroad has played a significant role in the city's development.  The railroad today bisects the commercial core of the city, which extends for several city blocks away from the railroad.  The historic district includes all of the major civic buildings of the city, including the courthouse, post office, and the old Prescott City Jail.

Supporting paragraphs: Baltimore and Philadelphia Railroad CSX Transportation
Answer: Jacksonville, Florida