With the exception of a short 61-mile segment in Greater Orlando (which is now state-owned), the entire line is owned by CSX Transportation.

[1] The main line was built in the late 1800s by the following companies: The process to combine these individual railroads into a unified system began around 1898.

[2] Due to increasing traffic and the Florida land boom of the 1920s, the ACL began work to double track 661 miles of the main line from Richmond to Jacksonville in 1922.

[2] In later years, much of the main line would be restored to single track with centralized traffic control and passing sidings.

In 1980, the Seaboard Coast Line's parent company merged with the Chessie System, creating the CSX Corporation.