List of Class I railroads
Today there are only handful of survivors ranked as Class I Railroads and a very different criteria for classification of railways by an entirely different governmental entity than the United States Interstate Commerce Commission, born amidst strong anti-trust movements. The original one million dollars of revenues per anum is hopelessly meaningless nowadays, as are the intervening steps when the ICC assigned revised ranking criteria. This is a list of current and former Class I railroads in North America under the older criteria and the newer as well as today's much different post-railroad consolidation classifications.
Current Class I's that are independently operating have their links in bold and further, have an asterisk (*) next to them. All the others are no longer ranked as Class I, and the entry here is merely historic. Today they may be current operating companies, or may be defunct, their operations turned into investments, some hanging onto a corporate skeleton owning properties as holding companies, or have assigned their properties in mergers, bankruptcy or other legal acts (dissolution of the corporation) and become extinct—their works either torn up and hopefully recycled, or sold off to operating companies. The reader must read to discern which by reading what is connected by hyperlinks. Many of the more famous small railways possessing key trunk lines have been merged into one of today's behemoths.
- Akron, Canton and Youngstown Railroad
- Alabama Great Southern Railroad
- Alabama, Tennessee and Northern Railroad
- Alabama and Vicksburg Railway
- Alton Railroad
- Amtrak *
- Ann Arbor Railroad
- Arizona Eastern Railroad
- Arizona and New Mexico Railway
- Atchison, Topeka and Santa Fe Railway
- Atlanta, Birmingham and Atlantic Railway
- Atlanta, Birmingham and Coast Railroad
- Atlanta and St. Andrews Bay Railway
- Atlanta and West Point Railroad
- Atlantic City Railroad
- Atlantic Coast Line Railroad
- Atlantic and Danville Railway
- Atlantic and St. Lawrence Railroad
- Auto-Train Corporation
- Baltimore, Chesapeake and Atlantic Railway
- Baltimore and Ohio Railroad
- Bangor and Aroostook Railroad
- Beaumont, Sour Lake and Western Railway
- Bessemer and Lake Erie Railroad
- Bingham and Garfield Railway
- Boston and Maine Corporation
- Boston and Maine Railroad
- Buffalo, Rochester and Pittsburgh Railway
- Buffalo and Susquehanna Railroad
- Burlington Northern Inc.
- Burlington Northern Railroad
- Burlington Northern and Santa Fe (BNSF) *
- Burlington-Rock Island Railroad
- Butte, Anaconda and Pacific Railway
- Cambria and Indiana Railroad
- Canadian National Railway *
- Canadian National Lines in New England
- Canadian Northern Railway
- Canadian Pacific Railway *
- Canadian Pacific Lines in Maine
- Canadian Pacific Lines in Vermont
- Carolina, Clinchfield and Ohio Railway
- Carolina and Northwestern Railway
- Central of Georgia Railway
- Central New England Railway
- Central Railroad of New Jersey
- Central Railroad of Pennsylvania
- Central Vermont Railway
- Charleston and Western Carolina Railway
- Chesapeake and Ohio Railway
- Chesapeake and Ohio Railway of Indiana
- Chicago and Alton Railroad
- Chicago, Burlington and Quincy Railroad
- Chicago, Detroit and Canada Grand Trunk Junction Railroad
- Chicago and Eastern Illinois Railroad
- Chicago and Erie Railroad
- Chicago Great Western Railroad
- Chicago and Illinois Midland Railway
- Chicago, Indiana and Southern Railroad
- Chicago, Indianapolis and Louisville Railway
- Chicago, Milwaukee and Puget Sound Railway
- Chicago, Milwaukee, St. Paul and Pacific Railroad (The Milwaukee Road)
- Chicago and North Western Transportation Company
- Chicago, Peoria and St. Louis Railroad
- Chicago, Rock Island and Gulf Railway
- Chicago, Rock Island and Pacific Railroad
- Chicago, St. Paul, Minneapolis and Omaha Railway
- Chicago Southern Railway
- Chicago, Terre Haute and Southeastern Railway
- Cincinnati, Hamilton and Dayton Railway
- Cincinnati, Indianapolis and Western Railroad
- Cincinnati, Lebanon and Northern Railway
- Cincinnati, New Orleans and Texas Pacific Railway
- Cincinnati Northern Railroad
- Cleveland, Akron and Cincinnati Railway
- Cleveland, Akron and Columbus Railway
- Cleveland, Cincinnati, Chicago and St. Louis Railway
- Clinchfield Railroad
- Coal and Coke Railway
- Colorado Midland Railroad
- Colorado Midland Railway
- Colorado and Southern Railway
- Colorado and Wyoming Railway
- Columbus and Greenville Railroad
- Columbus and Greenville Railway
- Consolidated Rail Corporation
- Copper River and Northwestern Railway
- Cripple Creek and Colorado Springs Railroad
- CSX Transportation *
- Cumberland Valley Railroad
- Cumberland Valley and Martinsburg Railroad
- Delaware and Hudson Company
- Delaware and Hudson Railroad
- Delaware and Hudson Railway
- Delaware, Lackawanna and Western Railroad
- Denver, Northwestern and Pacific Railway
- Denver and Rio Grande Railroad
- Denver and Rio Grande Western Railroad
- Denver and Salt Lake Railroad
- Denver and Salt Lake Railway
- Detroit, Grand Haven and Milwaukee Railway
- Detroit and Mackinac Railway
- Detroit, Toledo and Ironton Railroad
- Detroit, Toledo and Ironton Railway
- Detroit and Toledo Shore Line Railroad
- Duluth and Iron Range Railroad
- Duluth, Missabe and Iron Range Railway
- Duluth, Missabe and Northern Railway
- Duluth, South Shore and Atlantic Railway
- Duluth, Winnipeg and Pacific Railway
- El Paso and Southwestern Company
- Elgin, Joliet and Eastern Railway
- Erie Railroad
- Erie-Lackawanna Railroad
- Erie Lackawanna Railway
- Evansville, Indianapolis and Terre Haute Railway
- Evansville and Terre Haute Railroad
- Ferromex *
- Florence and Cripple Creek Railroad
- Florida East Coast Railway
- Fonda, Johnstown and Gloversville Railroad
- Fort Smith and Western Railroad
- Fort Smith and Western Railway
- Fort Worth and Denver Railway
- Fort Worth and Denver City Railway
- Fort Worth and Rio Grande Railway
- Galveston, Harrisburg and San Antonio Railway
- Georgia Railroad
- Georgia and Florida Railroad
- Georgia and Florida Railway
- Georgia Southern and Florida Railway
- Grand Canyon Railway
- Grand Rapids and Indiana Railway
- Grand Trunk Corporation
- Grand Trunk Western Railroad
- Grand Trunk Western Railway
- Great Northern Railway
- Green Bay and Western Railroad
- Gulf, Colorado and Santa Fe Railway
- Gulf, Mobile and Northern Railroad
- Gulf, Mobile and Ohio Railroad
- Gulf and Ship Island Railroad
- Hocking Valley Railway
- Houston East and West Texas Railway
- Houston and Texas Central Railroad
- Illinois Central Railroad
- Illinois Central Gulf Railroad
- Illinois Terminal Company
- Illinois Terminal Railroad
- Indianapolis Southern Railroad
- International-Great Northern Railroad
- International and Great Northern Railroad
- International and Great Northern Railway
- International Railway of Maine
- Iowa Central Railway