• Predecessors of the Atlantic Coast Line Railroad (71 P)
• Predecessors of the Baltimore and Ohio Railroad (35 P)
• Predecessors of the Chesapeake and Ohio Railway (1 C, 27 P)
• Predecessors of Conrail (16 C, 36 P)
• Predecessors of the Louisville and Nashville Railroad (2 C, 17 P)
• Predecessors of the Pittsburgh and Lake Erie Railroad (3 P)
• Predecessors of the Seaboard Air Line Railroad (72 P)
• Predecessors of the Western Maryland Railway (20 P)

P

• Pittsburgh and Lake Erie Railroad (3 C, 9 P)

S

• Seaboard Air Line Railroad (5 C, 57 P)
• Seaboard System Railroad (1 C, 11 P)

• List of CSX Transportation predecessor railroads

A

• Alexandria and Fredericksburg Railway
• Alexandria and Washington Railroad
• Alexandria and Washington Railway
• Atlanta and LaGrange Railroad
• Atlanta and West Point Railroad
• Atlantic Coast Line Railroad
• Augusta Belt Railway

B

• Baltimore and Ohio Railroad

C

• Carolina, Clinchfield and Ohio Railway
• Carolina, Clinchfield and Ohio Railway of South Carolina
• Chesapeake and Ohio Railway
• Chessie System
• Clinchfield Northern Railway
• Clinchfield Northern Railway of Kentucky
• Clinchfield Railroad
• Conrail

D

• Detroit and Howell Railroad
• Durham and Southern Railway

E

• Elkhorn Southern Railway

F

• Family Lines System

G

• Georgia Railroad
• Georgia Florida and Alabama Railroad
• Georgia Railroad and Banking Company

K

• Kanawha Bridge
• Kingsport Southern Railway

L

• Lick Creek and Lake Erie Railroad
• Louisville and Nashville Railroad

M

• Monon Railroad
• Montgomery Railroad
• Montgomery and West Point Railroad

N

• New York Central Lines LLC

P

• Piedmont and Northern Railway
• Pittsburgh and Lake Erie Railroad
• Potomac Railroad

R

• Richmond, Fredericksburg and Potomac Railroad

S

• SCL Industries
• Seaboard Air Line Railroad
• Seaboard Coast Line Industries
• Seaboard Coast Line Railroad
• Seaboard System Railroad
• South and Western Railroad
• South and Western Railway

W

• Washington Southern Railway
• West Virginia Central and Pittsburg Railway
• Western Maryland Railway
• Western Railway of Alabama