• Non-railway predecessors of railway companies (7 P)

A

• Predecessors of the Alton Railroad (9 P)
• Predecessors of the Ann Arbor Railroad (3 P)
• Predecessors of the Atchison, Topeka and Santa Fe Railway (1 C, 55 P)
• Predecessors of the Atlantic City Railroad (10 P)
• Predecessors of the Atlantic Coast Line Railroad (72 P)

B

• Predecessors of the Baltimore and Ohio Railroad (35 P)
• Predecessors of the Bessemer and Lake Erie Railroad (1 P)
• Predecessors of the BNSF Railway (4 C, 5 P)
• Predecessors of the Boston and Maine Railroad (45 P)
• Predecessors of the Brooklyn–Manhattan Transit Corporation (30 P)
• Predecessors of the Burlington Northern Railroad (6 C, 13 P)

C

• Predecessors of the Canadian Government Railways (2 C, 3 P)
• Predecessors of the Canadian National Railway (10 C, 21 P)
• Predecessors of the Canadian Northern Railway (10 P)
• Predecessors of the Canadian Pacific Railway (4 C, 21 P)
• Predecessors of the Central of Georgia Railway (37 P)
• Predecessors of the Central Railroad of New Jersey (2 C, 16 P)
• Predecessors of the Central Vermont Railway (17 P)
• Predecessors of the Chesapeake and Ohio Railway (1 C, 27 P)
• Predecessors of the Chicago and Eastern Illinois Railroad (6 P)
• Predecessors of the Chicago and North Western Transportation Company (2 C, 32 P)
• Predecessors of the Chicago Great Western Railway (3 P)
• Predecessors of the Chicago, Burlington and Quincy Railroad (1 C, 20 P)
• Predecessors of the Chicago, Rock Island and Pacific Railroad (15 P)
• Predecessors of the Colorado and Southern Railway (14 P)
• Predecessors of Conrail (16 C, 36 P)
• Predecessors of CSX Transportation (11 C, 47 P)

D

• Predecessors of the Delaware and Hudson Railway (23 P)
• Predecessors of the Delaware, Lackawanna and Western Railroad (20 P)
• Predecessors of the Denver and Rio Grande Western Railroad (10 P)
• Predecessors of the Detroit, Toledo and Ironton Railroad (2 P)
• Predecessors of the Duluth, Missabe and Iron Range Railway (1 C, 2 P)
• Predecessors of the Duluth, South Shore and Atlantic Railway (3 P)

E

• Predecessors of the Erie Railroad (25 P)

F

• Predecessors of the Florida East Coast Railway (5 P)

G

• Predecessors of the Grand River Railway (3 P)
• Predecessors of the Grand Trunk Railway (3 C, 39 P)
• Predecessors of the Great Northern Railway (U.S.) (10 P)
• Predecessors of the Gulf, Mobile and Ohio Railroad (1 C, 4 P)

I

• Predecessors of the Illinois Central Railroad (2 C, 19 P)
• Predecessors and affiliates of the Interborough Rapid Transit Company (12 P)
• Predecessors of the Intercolonial Railway (3 P)

K

• Predecessors of the Kansas City Southern Railway (12 P)

L

• Predecessors of the Lake Erie and Western Railroad (5 P)
• Predecessors of the Lehigh and New England Railroad (11 P)
• Predecessors of the Lehigh Valley Railroad (21 P)
• Predecessors of the Long Island Rail Road (21 P)
• Predecessors of the Louisville and Nashville Railroad (2 C, 17 P)

M

• Predecessors of the Maine Central Railroad (20 P)
• Predecessors of the Chicago, Milwaukee, St. Paul and Pacific Railroad (8 P)
• Predecessors of the Minneapolis and St. Louis Railway (3 P)
• Predecessors of the Minneapolis, St. Paul and Sault Ste. Marie Railroad (8 P)
• Predecessors of the Missouri Pacific Railroad (3 C, 35 P)
• Predecessors of the Missouri–Kansas–Texas Railroad (7 P)
• Predecessors of the Monon Railroad (1 P)

N

• Predecessors of the Nashville, Chattanooga and St. Louis Railway (7 P)
• Predecessors of the New York Central Railroad (2 C, 173 P)
• Predecessors of the New York, Chicago and St. Louis Railroad (2 C, 14 P)
• Predecessors of the New York, New Haven and Hartford Railroad (3 C, 79 P)
• Predecessors of the New York, Ontario and Western Railway (4 P)
• Predecessors of the New York, Susquehanna and Western Railway (4 P)
• Predecessors of the Norfolk and Western Railway (4 C, 44 P)
• Predecessors of the Norfolk Southern Railway (4 C, 8 P)
• Predecessors of the Norfolk Southern Railway (1942-1982) (14 P)
• Predecessors of the Northern Pacific Railway (10 P)
• Predecessors of the Northwestern Pacific Railroad (6 P)

P

• Predecessors of Pan Am Railways (2 C, 4 P)
• Predecessors of the Pennsylvania Railroad (2 C, 191 P)
• Predecessors of the Pennsylvania-Reading Seashore Lines (2 C, 13 P)
• Predecessors of the Pere Marquette Railway (41 P)
• Predecessors of the Pittsburgh and Lake Erie Railroad (3 P)

R

• Predecessors of the Reading Company (1 C, 29 P)
• Predecessors of the Rutland Railroad (9 P)

S

• Predecessors of the Sandy River and Rangeley Lakes Railroad (8 P)
• Predecessors of the Seaboard Air Line Railroad (72 P)
• Predecessors of the Southern Pacific Transportation Company (3 C, 66 P)
• Predecessors of the Southern Railway (U.S.) (3 C, 124 P)
• Predecessors of the Spokane, Portland and Seattle Railway (5 P)
• Predecessors of the St. Louis–San Francisco Railway (16 P)

T

• Predecessors of the Toledo, St. Louis and Western Railroad (5 P)

U

• Predecessors of the Union Pacific Railroad (10 C, 67 P)

V

• Predecessors of the Virginian Railway (2 P)

W

• Predecessors of the Wabash Railroad (15 P)
• Predecessors of the West Jersey and Seashore Railroad (18 P)
• Predecessors of the Western Maryland Railway (20 P)
• Predecessors of the Western Pacific Railroad (1 C, 7 P)