CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad company operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. Operating about 21,000 route miles () of track, it is the leading subsidiary of CSX Corporation, a Fortune 500 company headquartered in Jacksonville, Florida.

CSX Corporation was formed in 1980 from the merger of Chessie System and Seaboard Coast Line Industries, two holding companies that controlled railroads operating in the Eastern United States. Initially only a holding company, the subsidiaries that made up CSX Corporation completed merging in 1987. CSX Transportation formally came into existence in 1986, as the successor of Seaboard System Railroad. In 1999, CSX Transportation acquired about half of Conrail in a joint purchase with competitor Norfolk Southern Railway. In 2022, it acquired Pan Am Railways, extending its reach into northern New England.

Norfolk Southern remains CSX's chief competitor; the two share a duopoly on transcontinental freight rail lines in the east half of the US.

History

Predecessors

CSX is the result of a number of mergers among railroads operating in the eastern United States, the earliest among them the Baltimore and Ohio Railroad (B&O) which formed in the 1820s. Many of the competing railroads along the east coast began merging from the 1950s onward as part of a broader trend of consolidation. An announcement from the New York Central (NYC) and Pennsylvania (PRR) railroads in November 1957 that they were considering combining set off discussions between the Baltimore and Ohio Railroad and the Chesapeake and Ohio Railway (C&O) on a merger. Ultimately, the financially stronger C&O took control of the B&O in December 1962, though the two railroads kept their separate identities. The NYC and PRR ultimately formed Penn Central Transportation Company in 1968, which by 1970 was bankrupt.

The combined C&O/B&O purchased stock in the Western Maryland Railway until it was able to take full control in February 1967, bringing a third railroad into the combined entity, which in 1973 became formally known as the Chessie System after the C&O's historic cat mascot Chessie.

While the railroads in Appalachia were merging, southern railroads (and historical competitors) Seaboard Air Line Railroad and Atlantic Coast Line Railroad decided to pursue a merger in 1960, which was authorized by the Interstate Commerce Commission in late 1963 and finally completed in 1967, forming the Seaboard Coast Line Railroad. The combined company absorbed the Piedmont and Northern Railway in 1969.

In the Midwest, the Louisville and Nashville Railroad (L&N) went on an acquisition spree, splitting the Chicago and Eastern Illinois Railroad (C&EI) with the Missouri Pacific Railroad in 1969. This was followed in 1971 with the acquisition of the Monon Railroad, which had complained bitterly about the C&EI split. The L&N also purchased a portion of the Tennessee Central Railway in 1969. While still independent, the L&N had long standing links to the Atlantic Coast Line, and other railroads in the region began to worry about a combined L&N/SCL system.

In 1969, the Seaboard Coast Line created Seaboard Coast Line Industries as a holding company. The Seaboard Coast Line Railroad had already held some of L&N's stock, but the new holding company began buying up as much as it could find and held nearly total control of shares by 1971. With this also came control of the Clinchfield Railroad and Georgia Railroad, both of which were nominally jointly owned by SCL and L&N. The resulting railroad conglomerate began operating under the name "Family Lines".

Despite this wave of mergers, one more was yet to come—the combination of Chessie System and the Family Lines. To this end, the CSX Corporation was organized on November 14, 1978, as a future vehicle for such a merger. Chessie and SCL Industries formally applied for ICC approval of their merger plans in January 1979, causing a rapid reaction from the region's other railroads. By April, the Norfolk and Western Railway and Southern Railway unveiled their own plans for a merger. The Southern was opposed to the planned CSX merger, but soon came to terms with Chessie and SCL and dropped its objections. On November 1, 1980, following ICC approval, CSX Corporation officially came into being as the successor of Chessie System and Seaboard Coast Line Industries. In 1982, N&W and the Southern completed their merger and formed Norfolk Southern Railway, creating a competitor to CSX.

Early years

thumb|[[CSX Transportation Building in Jacksonville, Florida]]

thumb|Original logo for the [[CSX Corporation, emphasizing the "multiplication symbol" X]]

One of the first issues the new railroad grappled with was the choice of name. Chessie and SCLI leadership agreed that, as a merger of equals, neither of the existing names could be used. A call for suggestions went out to employees of both railroads, who responded with a wide variety of initialisms combining C and S in some form. At the same time, the two companies' lawyers needed a name to use as part of their proceedings with the ICC. "CSC" was chosen but belonged to a trucking company in Virginia. "CSM" (for "Chessie-Seaboard Merger") was also taken. Needing some sort of identifier for the new railroad, the lawyers decided to use "CSX", and the name stuck, despite only being intended as a placeholder. A fourth letter had to be added to CSX when used as a reporting mark (CSXT) because reporting marks that end in X mean that the car is owned by a leasing company or private car owner. Chessie's public relations staff drafted a number of possible logos for the new railroad, but continued to strike out until it was suggested to combine the letters "C" and "S" in the shape of an X.

In 2014, Canadian Pacific Railway approached CSX with an offer to merge the two companies, but CSX declined, and in 2015 Canadian Pacific made an attempt to purchase and merge with Norfolk Southern, but NS declined to do so as well.

thumb|A CSX Transportation EMD GP40-3 located in [[Knoxville]]

In 2017, CSX announced Hunter Harrison would become its new chief executive officer; a settlement with activist investor Paul Hilal and Mantle Ridge. CSX added five new directors to their board, including Harrison and Mantle Ridge founder Paul Hilal. Mantle Ridge owns 4.9% of CSX. Harrison quickly moved to convert CSX rail operations to precision railroading. On December 14, 2017, CSX announced that Hunter Harrison was on medical leave. Two days after the announcement, Harrison died, one day after being hospitalized for complications of an ongoing illness. CSX initially saw a 10% drop in its stock price, but turned around to hit a new 52-week high less than a month later (January 2018). Harrison's successors have continued the shift to precision railroading, with most hump yards converted to flat yards, low volume shipping lanes eliminated and reductions in rolling stock and work force.

In 2025, CSX completed two major infrastructure projects that had limited network capacity: repairs related to damage from Hurricane Helene and a large-scale tunnel renovation in Baltimore. These efforts had negatively affected train velocity and service performance over the past year.

Pan Am Railways acquisition

On November 30, 2020, CSX Transportation's parent company CSX Corporation announced on social media that they had come to an agreement with Pan Am Systems to purchase New England based Class II Pan Am Railways, pending regulatory approval from the Surface Transportation Board. The STB approved the purchase on April 14, 2022. As part of the acquisition, Norfolk Southern Railway will gain trackage rights over several CSX lines, and Pan Am Southern, 50 percent owned by Pan Am Railways, will be operated by the Berkshire and Eastern Railroad, a new Genesee & Wyoming subsidiary formed explicitly for this purpose.

Meridian and Bigbee Railroad acquisition

On June 28, 2023, CSX and the newly-formed Canadian Pacific Kansas City (CPKC) announced the intention to purchase Meridian and Bigbee Railroad (MNBR). The MNBR creates a connection between CSX in Burkville, Alabama, near Montgomery, and Meridian, Mississippi, where it joins the Meridian Speedway heading west. Under the proposed agreement, CSX will resume operations between Montgomery and Myrtlewood, terminating the lease currently in place with MNBR, while CPKC will acquire the segment of the line between Myrtlewood and Meridian. MNBR will cease operations between Montgomery and Myrtlewood although it may continue to operate between Myrtlewood and Meridian, and continue to serve existing customers on that segment of the line. If the STB approves the purchase, it will provide a connection between the two companies' networks and allow CSX traffic destined for Mexico to be delivered directly to CPKC, eliminating the need for a third intermediate railroad to move such traffic. Currently, CSX traffic bound for Mexico is exchanged with the Union Pacific Railroad in New Orleans, who then takes it to the cross-border gateway in Laredo, Texas, where it is delivered to CPKC.

In October 2024, the STB approved CSX's resumption of operations on the leased from M&B between Burkville and Myrtlewood and CPKC's purchase of the miles of line between Myrtlewood and Meridian. The agreement became effective on November 16, 2024.

Initially, and for the next five years, CSX and CPKC will interchange across the line an average of two trains per day in each direction.

Proposed merger with BNSF Railway or Canadian Pacific Kansas City

thumb|[[BNSF Railway|BNSF and CSX railroads]]

In August 2025, investor group Ancora Holdings urged the company to begin exploring a merger agreement with BNSF, the largest Class I railroad in the West, or CPKC, in response to the announced proposed mega-merger project between Union Pacific and Norfolk Southern.

At the same time, the investor group pressured the company to remove CEO and President Joe Hinrichs, citing the financial and operational decline of the railroad, among other claims. According to Trains.com, since Hinrichs joined CSX in 2022, the railroad has produced the best total shareholder returns among publicly traded Class I railroads. However, according to a March 2025 analysis by Trefis, CSX had a three-year compounded annual return of -3.7% over the period from 2021 to 2024. This was below the peer group's average return of -1.0% for the same period. According to an article in Semafor, "Hinrichs' performance over the last year was similarly lackluster. CSX's stock price was middle-of-the-pack, but it had lagged on key efficiency metrics." Hinrichs at several times asked for a pay increase for himself, which was $14 million annually.

Citigroup analyst Ariel Rosa was perplexed by Ancora's position it provided in a letter to CSX. The letter stated:

In response, Rosa wrote: