Common carriers (operating railroads)
{| class="wikitable sortable"
!
!
|-
|A ||Alton Railroad
|-
|AA ||Ann Arbor Railroad (1895-1976) → Ann Arbor Railroad (1988)
|-
|A&A ||Anniston and Atlantic Railroad
|-
|AAR ||Association of American Railroads<!--why does this have a common-carrier one?-->
|-
|AB ||Akron Barberton Cluster Railway
|-
|ABB ||Akron and Barberton Belt Railroad<!--earlier A&BB-->
|-<!--ABC Atlanta, Birmingham and Coast Railroad?-->
|ABCK||Alaska British Columbia Transportation Company
|-
|ABEC||Aberdeen Electric Company
|-
|ABL ||Alameda Belt Line
|-
|ABM ||Texas and Pacific Railway → Missouri Pacific Railroad<!--why?-->
|-
|ABN ||Alabama Northern Railway → Ashland Railway
|-
|ABPR||Aberdeen and Briar Patch Railway → Aberdeen, Carolina and Western Railway
|-
|ABR ||Athens Line
|-
|ABS ||Alabama Southern Railroad
|-
|AC ||Algoma Central and Hudson Bay Railway → Algoma Central Railway
|-
|ACBL||American Commercial Barge Lines
|-
|ACIS||Algoma Central Railway
|-
|ACJR||Ashtabula, Carson and Jefferson Railroad
|-
|ACL ||Atlantic Coast Line Railroad → Seaboard Coast Line Railroad → Seaboard System Railroad → CSX Transportation
|-
|ACRC||Andalusia and Conecuh Railroad
|-
|ACWR||Aberdeen, Carolina and Western Railway
|-
|ACY ||Akron, Canton and Youngstown Railroad → Norfolk and Western Railway → Norfolk Southern Railway
|-
|AD ||Atlantic and Danville Railway → Norfolk, Franklin and Danville Railway
|-
|ADBF||Adrian and Blissfield Railroad
|-
|ADIR||Adirondack Railway
|-
|ADN ||Ashley, Drew and Northern Railway → Arkansas, Louisiana and Mississippi Railroad
|-
|AE ||Arizona Eastern Railroad
|-
|AEC ||Atlantic and East Carolina Railway
|-
|AEFR||Aurora, Elgin and Fox River Electric
|-
|AER ||Algoma Eastern Railway
|-
|AERC||Albany and Eastern Railroad
|-
|AF ||Alabama and Florida Railway
|-
|AFLR||Alabama and Florida Railroad
|-
|AG ||Abbeville-Grimes Railway → A&G Railroad → Bay Line Railroad
|-
|AGCR||Alamo Gulf Coast Railroad
|-
|AGE ||Albertson Great Eastern Railroad
|-
|AGLF||Atlantic and Gulf Railroad → Knoxville and Holston River Railroad
|-
|AGR ||Alabama and Gulf Coast Railway
|-
|AGRD||A&G Railroad
|-
|AGS ||Alabama Great Southern Railroad
|-
|||Alberta and Great Waterways Railway
|-
|AHMR||Arlington Heights Motor Railway
|-
|AHT ||Alaska Hydro-Train
|-
|AHW ||Ahnapee and Western Railway → Fox Valley and Western Ltd.
|-
|AIRI||Alabama Industrial Railroad
|-
|AJ ||Alma and Jonquieres Railway
|-
|AJR ||Artemus-Jellico Railroad
|-
|AKC ||Arkansas Central Railroad
|-
|AKDN||Acadiana Railway
|-
|AKMD||Arkansas Midland Railroad
|-
|AL ||Almanor Railroad
|-
|ALAB||Alabama Railroad
|-
|||Arkansas, Louisiana and Gulf Railway
|-
|ALLN ||Allentown and Auburn Railroad
|-
|ALM ||Arkansas and Louisiana Midland Railway → Arkansas and Louisiana Missouri Railway → Arkansas, Louisiana and Mississippi Railroad<!--originally A&LM-->
|-
|ALQS||Aliquippa and Southern Railroad
|-
|ALS ||Alton and Southern Railroad → Alton and Southern Railway<!--originally AL&S-->
|-
|ALT ||Airlake Terminal Railway
|-
|ALU ||Alcolu Railroad
|-
|ALY ||Allegheny Railroad → Allegheny and Eastern Railroad
|-
|||Alabama and Mississippi Railroad
|-
|AM ||Arkansas and Missouri Railroad
|-
|AMC ||Amador Central Railroad
|-
|AMHR||Amherst Industries → Landisville Railroad
|-
|AMID||Alabama Midland Railway
|-
|AMR ||Arcata and Mad River Railroad
|-
|AMT||Agence métropolitaine de transport (Montréal, Québec)
|-
|AMTK||Amtrak (National Railroad Passenger Corporation)
|-
|AN ||Apalachicola Northern Railroad → AN Railway
|-
|ANC ||Atlantic and North Carolina Railroad
|-
|ANE ||Abbotsford and Northeastern Railroad
|-
|||Anthony and Northern Railway
|-
|ANR ||Angelina and Neches River Railroad
|-
|ANY ||Athabasca Northern Railway
|-
|AO ||Appalachian and Ohio Railroad
|-
|AOK ||Arkansas-Oklahoma Railroad
|-
|AOR ||Aliquippa and Ohio River Railroad
|-
|APA ||Apache Railway
|-
|APD ||Albany Port District
|-
|APNC||Appanoose County Community Railroad
|-
|AR ||Aberdeen and Rockfish Railroad
|-
|ARA ||Arcade and Attica Railroad
|-
|ARC ||Alexander Railroad
|-
|ARDP||Missouri Pacific Railroad → Union Pacific Railroad<!--why?-->
|-
|ARE ||A&R Line
|-
|ARMD||Arnaud Railway
|-<!--Armour Refrigerator Line was initially ARL, probably before X was set aside-->
|ARMH||Missouri Pacific Railroad → Union Pacific Railroad<!--why?-->
|-
|ARMN||Missouri Pacific Railroad → Union Pacific Railroad<!--why?-->
|-
|ARN ||Alberta RailNet → Canadian National Railway
|-
|ARR ||Alaska Railroad
|-
|ARRG||Altra Railroad
|-
|ARS ||Arkansas Southern Railroad
|-
|ART||American Refrigerator Transit Company
|-<!--American Refrigerator Transit was initially ART, probably before X was set aside-->
|ARW ||Arkansas Western Railway
|-
|ARZC||Arizona and California Railroad
|-
|AS ||Abilene and Southern Railway → Missouri Pacific Railroad<!--originally A&S-->
|-
|||Atlanta and St. Andrews Bay Railway
|-
|ASAB||Atlanta and St. Andrews Bay Railway → Bay Line Railroad
|-
|ASDA||Asbestos and Danville Railway
|-
|ASML||Atlanta, Stone Mountain and Lithonia Railway
|-
|ASR ||Allegheny Southern Railroad
|-
|ASRW||Allegheny Southern Railway
|-
|ASRY||Ashland Railway
|-
|AT||Auto Train
|-
|ATCO||Arnold Transit
|-<!--Armour Tank Line was initially ATL, probably before X was set aside-->
|ATLT||AT&L Railroad
|-
|ATN||Alabama & Tennessee River Railway
|-
|ATR ||Alliance Terminal Railroad
|-
|ATRW||Anthracite Railway
|-
|ATSF||Atchison, Topeka and Santa Fe Railway → BNSF Railway
|-
|ATW ||Atlantic and Western Railway
|-
|AUAR||Austin Area Terminal Railroad
|-
|AUG ||Augusta Railroad
|-
|AUNW||Austin and Northwestern Railroad
|-
|AUS ||Augusta Southern Railroad
|-
|AUS ||Augusta and Summerville Railroad
|-
|AUT ||Autauga Northern Railroad
|-
|||Alabama and Vicksburg Railway
|-
|AVNE||Avera & Northeastern Railroad
|-
|AVL ||Aroostook Valley Railroad
|-
|AVR ||Allegheny Valley Railroad
|-
|AVRR ||AG Valley Railroad
|-
|||Alexandria and Western Railway
|-
|AW ||Ahnapee and Western Railway
|-
|AWP ||Atlanta and West Point Railroad → Seaboard System Railroad → CSX Transportation<!--originally A&WP-->
|-
|AWRR||Austin Western Railroad
|-
|AWW ||Algers, Winslow and Western Railway
|-
|AYSS||Allegheny and South Side Railway
|-
|AZER||Arizona Eastern Railway
|-
|AZS ||Arizona Southern Railroad
|}
Others (assigned to companies or individuals who own railcars, but are not operating railroads)
{| class="wikitable sortable"
!
!
|-
|AAAX||Ann Arbor Railroad (1895-1976) → Ann Arbor Railroad (1988)
|-
|AACX||Alaska Division of Agriculture)
|-
|AADX||Airco Alloys and Carbide
|-
|AAEX||American Aniline and Extract Company
|-
|AAIX||ACS International Inc
|-
|AAKX||Amulco Asphalt Company
|-
|AALX||Advanced Aromatics
|-
|AAMX||Shippers' Car Line Division of ACF Industries; Arrendadora de Carros de Ferrocarril del Atlantico; Arrendadora de Carros de Ferrocarril
|-
|AARX||Association of American Railroads
|-
|AATX||Ampacet Corporation
|-
|AAX ||American Agricultural Chemical Company; Agrico Chemical Company
|-
|ABBX||Abbott Labs
|-
|ABCX||American Bitumuls Company; Merchants Despatch Transportation Corporation; Falcon Coal Company; Tennessee Valley Authority
|-
|ABEX||Abbey Chemical Corporation; CPS Processing Corporation; CPS Chemical Company; Abbey Chemical Corporation; Advanced BioEnergy
|-
|ABGX||American Black Granite Company
|-
|ABIX||Anheuser-Busch
|-
|ABLX||American Refrigerator Transit Company
|-
|ABMX||Albers Brothers Milling Company
|-
|ABOX||American Rail Box Car Company; Railbox Company; TTX Company
|-
|ABPX||Ashland By-Product Coke Company; Animal By-Products Corporation
|-
|ABRX||Merchants Despatch Transportation Corporation; AB Rail Investments, Inc.; Railmark Holdings, Inc.
|-
|ABSX||American Beet Sugar Company; American Crystal Sugar Company; Albert Brothers Inc
|-
|ABTX||Aubrey Bartlett; North American Car Corporation; General Electric Railcar Services Corp.
|-
|ABWX||Asea Brown Boveri, Inc.
|-
|ABX ||Adirondack Bottled Gas Corporation; Home Gas Corporation of Great Barrington
|-
|ACAX||Aluminum Company of America; Allied Chemical Canada; Allied Chemical Corporation; Honeywell International
|-
|ACBX||Scandinavian Oil Company; American Cast Iron Pipe Company
|-
|ACCX||Ansul Chemical Company; Consolidation Coal Company
|-
|ACDX||Allied Chemical Corporation; First Union Properties; Allied Chemical Corporation; Allied Signal; Honeywell International
|-
|ACEX||Atlantic City Electric Power Company; Atlantic Cement Company; Blue Circle Atlantic; Ace Cogeneration Company
|-
|ACFX||ACF Industries; General Electric Rail Services Corporation; Wells Fargo Rail
|-
|ACGX||Acme Gas Corporation; Suburban Propane, LP
|-
|ACIX||Arkansas Chemicals, Inc.; Great Lakes Chemical Corporation
|-
|ACJU||American Coastal Lines Joint Venture, Inc.
|-
|ACLU||Atlantic Container Line, Ltd.
|-
|ACLX||American Car Line Company
|-
|ACMX||Allis-Chalmers Corporation; Voith Hydro
|-
|ACNU||AKZO Chemie, B V
|-
|ACOU||Associated Octel Company, Ltd.
|-
|ACOX||Aurora Cooperative Elevator Company (grain shippers)
|-
|ACPX||Amoco Canada Petroleum Company, Ltd.; Amoco Oil Company; Union Tank Car Lines
|-
|ACPZ||American Concrete Products Company
|-
|ACRX||American Chrome and Chemicals, Inc.; Elementis Chromium, LP
|-
|ACSU||Atlantic Cargo Services, AB
|-
|ACSX||First Union Properties, Inc.; Honeywell International
|-
|ACSZ||American Carrier Equipment
|-
|ACTU||Associated Container Transport (Australia), Ltd.
|-
|ACTX||Allied Chemical Corporation; Honeywell International
|-
|ACUU||Acugreen Limited
|-
|ACWZ||Union Pacific Railroad
|-
|ACXU||Atlantic Cargo Services, AB
|-
|ACXX||Anderson Columbia Company, Inc.
|-
|ACZX||A C Railroad Service Company, Norfolk Southern Railway Company
|-
|ADCU||Flexi-Van Leasing, Inc.
|-
|ADCX||Adolph Coors Company
|-
|ADIX||Adirondack Railway Preservation Society (Adirondack Scenic Railroad)
|-
|ADKU||AGA A/S
|-
|ADMX||Archer Daniels Midland
|-
|ADRX||Addeleston Recycling Corporation
|-
|ADSX||Andrew Merrilees, Ltd.
|-
|AECX||Associated Electric Cooperative, Inc.
|-
|AEIX||Alan Eslisk
|-
|AEIZ||Farrell Lines, Inc.
|-
|AEPU||American Lines, Inc.
|-
|AEPX||American Electric Power Service Corporation
|-
|AEQX||ATEL Equipment Corporation
|-
|AESX||A. E. Staley Manufacturing; GE Railcar Services Corporation
|-
|AEVX||AKZO Coatings, Inc.
|-
|AEX||The Andersons
|-
|AFCU||Afram Lines, Inc.
|-
|AFCX||Atel Capital Equipment Fund
|-
|AFCZ||Afram Lines, Inc.
|-
|AFEX||Farmers Elevator Company of Arthur, ND
|-
|AFFX||AFFCAR, Inc.
|-
|AFIU||ABS Industrial Verification, Inc.
|-
|AFIZ||Agmark Foods
|-
|AFPX||Fibers and Plastics Company (Allied Corporation); Honeywell International
|-
|AFRX||AF Railway Industries, Inc.
|-
|AFSX||Astoria, LLC
|-
|AFTX||American Freedom Train
|-
|AGCX||Alberta Gas Chemicals, Inc.; PROCOR
|-
|AGEX||A. G. Pipe Lines, Inc.; Nova Chemicals, Ltd.
|-
|AGFX||Anchor Gas and Fuel Company, Inc.
|-
|AGHX||Agrium US, Inc.
|-
|AGIX||AGRI Financial Services, Inc.; AGRI Industries
|-
|AGLX||Andrews Gas Liquids Service; Andrews Petroleum
|-
|AGMX||Terra Nitrogen, LP
|-
|AGPX||AG Processing, Inc.
|-
|AGRX||Agrifos, LLC
|-
|AGYX||American Gypsum Company; Centrex Construction Products, Inc.
|-
|AHCX||Arcadian Corporation
|-
|AHMX||Altos Homos de Mexico, SA de CV
|-
|AHWZ||Fox Valley and Western
|-
|AICX||Hoeganaes Corporation
|-
|AIDU||Albermarle Corporation<!--sources say Albermarle but probably Albemarle Corporation-->
|-
|AIEU||Aviation Import Export, Inc.
|-
|AIIZ||III Transportation
|-
|AIMX ||American Iron & Metal Company
|-
|AINX||TTX Company (Acorn Division)
|-
|AIPX||Atlas Iron Processors, Inc.
|-
|AITU||Western Intermodal
|-
|AJCU||Australia Japan Container Line
|-
|AJPX||North American Chemical Company; IMC Chemicals
|-
|AKFX||AKF Corporation
|-
|AKLU||K Line
|-
|AKMX||Helm Financial Corporation
|-
|AKZX||Azko Nobel Chemicals, Inc.
|-
|ALAX||Lyondell Petrochemical; Equistar Chemicals, LP
|-
|ALBX||Albert City Elevator
|-
|ALCX||Aluminum Company of Canada, Ltd.; Alcan Smelters and Chemicals, Ltd.
|-
|ALEX||AGRI Financial Services, Inc.; AGRI Industries
|-
|ALGX||Amsterdam Leasing
|-
|ALKX||Airlake Terminal Railway Company
|-
|ALLX||Alliance Machine Company
|-
|ALLZ||Alliance Shippers
|-
|ALMX||Trinity Rail Management, Inc.
|-
|ALNX||Government of Alberta
|-
|ALPX||Government of Alberta
|-
|ALRX||A and R Leasing, LLP
|-
|ALSX||Albis Canada, Inc.
|-
|ALTU||VTG Vereinigte Tanklage U Transportmittel, GMBH
|-
|ALTX||Southern Illinois Railcar, Inc.
|-
|ALUX||Alumax of South Carolina, Inc.
|-
|ALWX||GE Railcar Services Corporation
|-
|AMAX||AMAX Coal Company
|-
|AMBU||Amber Line, Inc.
|-
|AMBX||Amherst Industries, Inc.; American Boiler Works, Inc.
|-
|AMCX||Amoco Chemicals Corporation; Amoco Oil Company; BP Amoco Chemical Company (Chemical Division)
|-
|AMCZ||Interbulk, Inc.
|-
|AMEX||Albamex; Allied Enterprises
|-
|AMFU||Amphibious Container Leasing, Ltd.
|-
|AMGX||AMG Resources Corporation
|-
|AMIU||American Marine Industries
|-
|AMIX||Railcar Leasing Specialists, Inc.
|-
|AMIZ||American Marine Industries
|-
|AMLX||American Railcar Company
|-
|AMMU||Hyundai
|-
|AMMX||Amoco Minerals Company; Kentucky-Tennessee Clay Company
|-
|AMNX||American Railcar Leasing Partners
|-
|AMOX||Amoco Oil Company; BP Products North America, Inc.
|-
|AMOZ||American Oil Company
|-
|AMPX||GE Railcar Services Corporation
|-
|AMRU||Alaska Marine Lines, Inc.
|-
|AMRX||Consolidated Oil and Transportation Company, Inc.
|-
|AMRZ||American Chassis Leasing, Inc.
|-
|AMSX||AllTrans Management Services Corporation
|-
|AMTZ||Amtrak
|-
|AMWX||Amway Corporation
|-
|AMXU||Americas Marine Express, Inc.
|-
|ANAU||Alliance Navigation Line, Inc.
|-
|ANAX||Excel Railcar Corporation; GE Rail Services Corporation
|-
|ANBX||Anbel Corporation
|-
|ANCX||Norit Americas, Inc.
|-
|ANDX||Andesite Rock Company
|-
|ANIX||Associacion National de la Industria Quimca, A.C.
|-
|ANKX||A and K Railroad Materials, Inc.
|-
|ANSX||Ansco Investment Company
|-
|AOCU||Associated Octel
|-
|AOCX||Aluminum Company of America (Alcoa)
|-
|AOEX||American Orient Express Railway
|-
|AOIX||Marathon Ashland Petroleum Company
|-
|AOKX||Greenbrier Management Services, LLC
|-
|AOUX||Alberta and Orient Glycol Company, Ltd.
|-
|APAX||West Penn Power Company; Cementos Apasco, SA de CV
|-
|APAXX||Cementos Apasco, SA de CV
|-
|APCU||American President Lines, Ltd.
|-
|APCX||Allied Products Company; Allied Lime Company
|-
|APEX||Apex Tank Car Line
|-
|APHX||Air Products Polymers, LP
|-
|APIX||The Commonwealth Plan, Inc.
|-
|APLU||American President Lines, Ltd.
|-
|APLX||APL Land Transport Services, Inc.
|-
|APLZ||American President Lines, Ltd.
|-
|APMU||Maersk Lines
|-
|APMX||Air Products Manufacturing Company
|-
|APMZ||Maersk Equipment Service Company
|-
|APOX||Alabama Power Company
|-
|APRX||Air Products
|-
|APSX||Arizona Public Service Company
|-
|APTX||Air Products
|-
|APWX||Appalachian Power Company
|-
|APXX||Alberta Prairie Railway Excursions
|-
|AQCX||Aqua-Chem, Inc. (Celaver Brooks Division)
|-
|ARCX||Alaska Rail Car Company; Arizona Rail Car, Inc.
|-
|ARDU||CATU Containers, SA
|-
|AREX||Aeropres Corporation
|-
|ARGX||Associated Railcar, Inc.
|-
|ARHU||CATU Containers, SA
|-
|ARHX||Arch Mineral Corporation
|-
|ARIX||Arco Industrial Gases (a division of Arco, Inc.); GE Rail Services Corporation
|-
|ARJX|| Arch Chemicals
|-
|ARL||Armour Refrigerator Line (expired)
|-
|ARMH||Missouri Pacific Railroad; Texas-New Mexico Railway; Doniphan, Kensett and Searcy Railway; Missouri Pacific Railroad; Union Pacific Railroad
|-
|ARMN||Missouri Pacific Railroad; Union Pacific Railroad
|-
|ARMX||American Rail and Marine Corporation
|-
|ARMZ||Armasal Line
|-
|AROX||GATX Corporation
|-
|ARPX||Arco Petroleum Products Company; BP Products North America, Inc.
|-
|ARRX||Anaconda Minerals Company; Anthracite Railroads Historical Society, Inc.
|-
|ARSX||Aristech Chemical Corporation; Sunoco, Inc.
|-
|ARTU||CATU Containers, SA
|-
|ARWX||Alabama River Woodlands, Inc.
|-
|ASCX||Algoma Steel Corporation; Armco Steel Company, LP
|-
|ASDX||Allied Services
|-
|ASGX||American Steel Foundries, Inc.
|-
|ASHU||Anchorage Sand and Gravel Company; Ash Grove Cement Company
|-
|ASHC||Maritainer France, SA
|-
|ASHX||General American Transportation Corporation; American Soda, LLP
|-
|ASLX||Algoma Steamships, Ltd.
|-
|ASMX||Ames And Sons Machine Works
|-
|ASRX||Amstar Corporation; Domino Sugar Company
|-
|ASRZ||Agri/Share Cooperative
|-
|ASTX||ASARCO
|-
|ASYX||Avondale Shipyards, Inc.
|-
|ATAX||Arizona Transit Assembly; Alameda Corridor Transportation Authority
|-
|ATCX||Austin and Texas Central Railroad; Southern Illinois Railcar, Inc.
|-
|ATEX||Asplundh Tree Expert Company (Railroad Division)
|-
|ATGU||Burlington Northern and Santa Fe Railway; BNSF Railway
|-
|ATGX||ATEL Leasing Corporation
|-
|ATIU||Societe Auxillaire De Transport Et D'Industries
|-
|ATIX||Alstom Transportation, Inc.
|-
|ATLU||American Marine Industries
|-
|ATLX||Atlas Machine and Iron Works, Inc.
|-
|ATLZ||American Marine Industries
|-
|ATMX||United States Department of Energy (Albuquerque Operations Office)
|-
|ATOU||Atochem
|-
|ATTX||Trailer Train Company; TTX Corporation
|-
|AUBX||US Plastic Lumber, Ltd.
|-
|AVCX||AVCO Aerostructures Division
|-
|AVLU||Allied Van Lines
|-
|AWCX||Airco Welding Products
|-
|AWDX||Atlantic of New York, Inc.
|-
|AWIX||Albright and Wilson Americas, Inc.
|-
|AWVX||20th Century Fox
|-
|AWXX||East Carbon Development Company
|-
|AWZZ||McCloud Railway Company
|-
|AXCU||Ace Transportation Company
|-
|AXXZ||Agricultural Express of America
|-
|AZCX||Azcon Corporation
|-
|AZEX||Arizona Electric Power Cooperative, Inc.
|-
|AZMX||Arizona Railway Museum
|-
|AZXX||Arizona Chemical Company
|}
References
- Reporting Marks: A
- [http://www.rrpicturearchives.net/railroadList.aspx?tid=10]