This child group collects United States Railroads members headquartered or historically based in the South Atlantic Census division (Delaware, Maryland, Virginia, West Virginia, North Carolina, South Carolina, Georgia and Florida), one of the two largest of the nine divisional child groups this atlas splits the parent group into. It spans modern Class I carriers headquartered in the division (Norfolk Southern Corporation of Atlanta, CSX Corporation of Jacksonville, Amtrak of Washington), historic Southeastern trunk lines (Southern Railway, the Seaboard Air Line Railroad, the Atlantic Coast Line Railroad and their successor the Seaboard System Railroad, the Western and Atlantic Railroad, the Richmond, Fredericksburg and Potomac Railroad, the Georgia Railroad and Banking Company), the Baltimore and Ohio Railroad, headquartered in Baltimore, Maryland, and the Delaware and Hudson Railway and Erie Lackawanna Railway. At 67 members it sits under this atlas's oversized-group threshold and needs no further split at this time.