ACL
| Atlantic Coast Line | 7 |
AMTK
| Amtrak | 8 |
ARR
| Alaska Railroad | 1 |
ATSF
| Atchison Topeka & Santa Fe | 6 |
BM
| Boston & Maine | 1 |
BML
| Belfast & Mooshead Lake | 2 |
BO
| Baltimore & Ohio | 3 |
CBQ
| Chicago Burlington & Quincy | 3 |
CNJ
| Central Rail Road of New Jersey | 2 |
CO
| Chesapeake & Ohio | 2 |
CR
| Conrail | 2 |
DH
| Delaware & Hudson | 1 |
DRGW
| Denver & Rio Grande Western | 1 |
EL
| Erie Lackawanna | 6 |
GN
| Great Northern | 5 |
ICG
| Illinois Central Gulf | 5 |
KCS
| Kansas City Southern | 1 |
MB
| Meridian & Bigbee | 2 |
NH
| New Haven | 5 |
NKP
| Nickel Plate | 1 |
NYC
| New York Central | 6 |
PRR
| Pennsylvania Railroad | 2 |
RDG
| Reading Railroad | 1 |
REX
| Railway Express Agency, Inc. | 2 |
SAL
| Seaboard Air Line | 1 |
SCL
| Seaboard Coast Line | 1 |
SLSF
| Saint Louis-San Francisco | 1 |
SP
| Southern Pacific | 1 |
UP
| Union Pacific Railroad Company | 1 |
WWRC
| Wilmington and Western Railroad | 5 |