The Charleston Subdivision is a portion of the Florence Division that includes part of CSX's A Line, one of their main lines which ultimately extends from Richmond, Virginia, to Tampa, Florida. Charleston Subdivision also includes a flat switching yard in North Charleston named Bennett Yard, as well as a satellite yard located in downtown Charleston called Cooper Yard which primarily holds tanks.
The line south of Johns Island (just southwest of Charleston) was originally chartered in 1854 by the Charleston and Savannah Railroad (later known as the Charleston and Savannah Railway).[4]
The line from North Charleston to Johns Island, including the bridge over the Ashley River, was built as the Ashley River Railroad, which opened in on December 27, 1877. This was the final link in what would become the Atlantic Coast Line Railroad mainline (the CSX A Line).[5]
In 1967, the Atlantic Coast Line (ACL) and its competitor, the Seaboard Air Line Railroad (SAL) merged to create the Seaboard Coast Line Railroad (SCL). The first few months after the merger, the line was known as the Southover Subdivision. This was due to the fact that a nearly parallel ex-SAL route still existed just to the east from Charleston to Savannah (the East Carolina Line). This line was still designated as the Charleston Subdivision (which the SAL named it prior to the merger).[7] Though, a few months after the merger, the ex-SAL route was severed as a through route and the SCL then used the Charleston Subdivision designation to rename the Southover Subdivision.[8]
In 1980, the Seaboard Coast Line's parent company merged with the Chessie System, creating the CSX Corporation. The CSX Corporation initially operated the Chessie and Seaboard Systems separately until 1986, when they were merged into CSX Transportation.