CSX is not the same as the Chessie System, but it is the direct successor. In 1980, the Chessie System (which included the B&O and C&O railroads) merged with Seaboard Coast Line Industries to form the CSX Corporation. For several years, "Chessie" and "Seaboard" operated as separate entities under the CSX umbrella until 1986, when they were officially consolidated into CSX Transportation. In 2026, the famous "Chessie the Cat" logo is still fondly remembered as a part of the company's heritage, but the "C" in CSX stands for "Chesapeake," the "S" for "Seaboard," and the "X" for "Multiplied"—symbolizing the synergy of the merger. While CSX has modernized its fleet significantly, much of the rail infrastructure in the Eastern U.S. that it operates today was originally built by the legendary railroads of the Chessie System.