Grootspoor Ondernemingen (Maatschappijen) USA Hedendaagse Ondernemingen (Maatschappijen): Amtrak - Alaska Railroad (ARR) - Burlington Northern and Santa Fe Railway (BNSF) - Canadian National Railway Company (CN) - CSX Transportation (CSXT) - Norfolk Southern Railway (NS) - Union Pacific Railroad (UP) Historische Ondernemingen (Maatschappijen): ATSF (Santa Fe) - Atlantic and Pacific Railroad (A&P) - Baltimore and Ohio Railroad (B&O) - Chesapeake and Ohio Railway (C&O) - Chessie System - Colorado Midland Railway (CM) - Colorado and Southern Railway (CS) - Conrail - Denver & Rio Grande Western Railroad (DRGW) - Erie Railroad - Missouri Pacific Railroad (MP) - New York Central Railroad (NYC) - Nickel Plate Road (NKP) - Northern Pacific Railway (NP) - Northwestern Pacific Railroad (NWP) - Penn Central (PC) - Pennsylvania Railroad (PRR) - Pere Marquette Railway (PM) - Southern Pacific Transportation Company (SP) - Southern Railway Company (SOU) - Spokane, Portland & Seattle Railway (SP&S) - St. Louis–San Francisco Railway (SLSF of Frisco) - Texas and Pacific Railway (T&P) - Toledo, Peoria & Western Railroad (TP&W) - Western Maryland Railway (WM) - Western Pacific Railroad (WP)