The Atlanta, Birmingham and Coast Railroad was organized in 1926 to replace the bankrupt Atlanta, Birmingham and Atlantic Railway. The AB&C was controlled by the Atlantic Coast Line Railroad, which owned a majority of the stock. In 1944 it reported 763 million net ton-miles of revenue freight and 33 million passenger-miles; at the end of that year it operated 639 miles of road and 836 miles of track.

The Atlantic Coast Line Railroad was a United States Class I railroad formed in 1900, though predecessor railroads had used the ACL brand since 1871. In 1967, it merged with long-time rival Seaboard Air Line Railroad to form the Seaboard Coast Line Railroad. Much of the original ACL network has been part of CSX Transportation since 1986.