From american-rails: original owners
Chances are your favorite railroad had them at some point in time
***Ironically the UP was one of the very few that never touched the rs3, but bought it's cousin, the rs2
Alco Demonstrators (3)
Alton & Southern
American Smelting & Refining
Atlantic & Danville
Birmingham Southern
Blue Ridge Railway
Boston & Maine
Carolina & North-Western
Central Of Georgia
Central Railroad Of New Jersey
Central Vermont
Chesapeake & Ohio
Chicago & North Western
Cincinnati, New Orleans & Texas Pacific (Southern)
Chicago, St. Paul, Minneapolis & Omaha (C&NW)
Danville & Western
Delaware & Hudson
Delaware, Lackawanna & Western (Lackawanna)
Denver & Rio Grande Western
Erie
Federal Barge Lines
Grand Trunk Western
Great Northern
Green Bay & Western
Gulf, Mobile & Ohio
Interstate Railroad
Kennecott Copper
Lake Superior & Ishpeming
Lehigh & Hudson River
Lehigh Valley
Litchfield & Madison
Long Island Rail Road
Louisville & Nashville
Macon, Dublin & Savannah
Maine Central
Milwaukee Road
Minnesota Transfer
Missouri-Illinois Railway
Missouri-Kansas-Texas (Katy)
Missouri Pacific
New Haven
New Orleans & Northeastern (Southern)
New York Central
Nickel Plate Road
Norfolk & Western
Northern Pacific
Oliver Iron Mining
Pennsylvania
Piedmont & Northern
Pittsburgh & Lake Erie (NYC)
Reading
Rock Island
Rutland
Soo Line
St. Louis Southwestern (Cotton Belt)
St. Marys Railroad
San Manuel Copper
Seaboard Air Line
Southern
Spokane, Portland & Seattle
Tennessee Central
Terminal Railroad Association of St. Louis (TRRA)
Texas Pacific-Missouri Pacific Terminal
Toledo, Peoria & Western
Western Maryland
Yadkin Railroad
(Canadian Built, MLW)
Quebec, North Shore & Labrador Railway
Ontario Northland
Central of Brazil
Pacific Great Eastern
Canadian National
Canadian Pacific
Roberval & Saguenay
“A designer must always think about the unfortunate production engineer who will have to manufacture what you have designed; try to understand his problems.” - Raymond Loewy