CSX Transporation, Inc. is a railroad in the United States. The parent company of CSX Transportation is CSX Corporation. CSX was formed in 1987 from a merger of the Chessie System and Seaboard System. The Chessie System in turn was formed from the Chesapeake and Ohio Railway, the Baltimore and Ohio and Western Maryland Railroad. Seaboard System was formed from the Louisville and Nashville Railroad (L&N), the Seaboard Coast Line Railroad, Clinchfield Railroad, and some smaller lines.
Today the CSX is one of seven remaining Class I freight railroads  in the United States and Canada, along with Norfolk Southern, Burlington Northern Santa Fe, Kansas City Southern, Union Pacific, Canadian National Railway, and Canadian Pacific Railway. Most of the other well known railroad lines have merged into one of these seven remaining Class I lines.
In 1999 the assets of Conrail were divided between CSX and Norfolk Southern. Conrail was a U.S. government run railway which comprised the former assets of the Pennsylvania Railroad and New York Central (which had merged in 1968 to become the Penn Central only to declare bankruptcy in 1970), Erie Lackawanna, Ann Arbor Railroad, Lehigh Valley Railroad, and several others which had all declared bankruptcy in the early 1970s.