A major East Coast railroad system, formed in 1972 by the merger of the C&O, the B&O (the oldest railroad in the US, and a Monopoly property), and the Western Maryland.
The new name ws inspired by Chessie, the mascot (a kitten) for the C&O's passenger service in the 1930s and 1940s. The corporate logo was a stylised version of the famous (at least to railfans) picture of Chessie snoozing on a pillow.
Chessie merged with the Seaboard System in 1980 to form CSX.