| 1 | GATX | General American Marks Co. | added 1/1998; 7/2000-7/2005 | | NAKINA |
| 2 | GATX | General American Transportation Corp. | 4/1938-1/1980; added 7/1984; 1/1994; eliminated 1/1998 | | NAKINA |
| 3 | GATX | General American Tank Line (General American Transportation Corp.) | 7/1937 | | NAKINA |
| 4 | GATX | General American Tank Line (General American Tank Car Corp.) | 8/1920-7/1935 | | NAKINA |
| 5 | GATX | General American Tank Line (General American Transportation Corp.) | 4/38-10/66 | | NRHS |
| 6 | GATX | General American Transportation Corp. | 4/70-1/80; added 7/84; 1/94; eliminated 1/98 | | NRHS |
| 7 | GATX | General American Marks Co. | added 1/98; 7/2000 | | NRHS |
| 8 | GATX | GENERAL AMERICAN MARKS COMPANY (GATX CORP.) [GENERAL AMERICAN TANK LINE] | | | PWRC |
| 9 | GATX | GATX Corporation | | | RSRV |
| 10 | GATX | GENERAL AMERICAN MARKS COMPANY | | | SCAC4 |
| 11 | GATX | General American Tank Line (General American Transportation Corp.) | | USA | TRAFFIC |
| 12 | GATXA | GATX Rail Austria GmbH | | AT | VKM |
| 13 | GATXD | GATX Rail Germany GmbH | | DE | VKM |
| 14 | GATXO | Ing. Alica Ovčiariková A.O., s.r.o. | | SK | VKM |
| 15 | GATXP | GATX Rail Poland Sp. z o.o. | | PL | VKM |
