The Portsmouth Subdivision is a railroad line owned by CSX Transportation in Virginia and North Carolina.

[1][2] The Portsmouth Subdivision was historically operated by the Seaboard Air Line Railroad, a CSX predecessor.

From Portsmouth, it runs southwest to Garysburg, North Carolina on the Roanoke River, a distance of 75.8 miles.

Its connection from Roanoke Rapids north to Gaston was permanently severed during the American Civil War.

[3][4] The extension to Weldon connected with the Seaboard and Roanoke Railway, essentially making a continuous line.

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