| 1 | C&A | Alton R.R. | 4/1938-7/1954 | | NAKINA |
| 2 | C&A | The Chicago and Alton R.R. Co. (The Alton R.R. Co.) | 7/1932-7/1936 | | NAKINA |
| 3 | C&A | The Chicago and Alton R.R. Co. | 8/1920-7/1930 | | NAKINA |
| 4 | C&A | The Chicago and Alton R.R. Co. | 23-Jul | | NRHS |
| 5 | C&A | Alton R.R. | 4/38-1/52 | | NRHS |
| 6 | C&A | CHICAGO & ALTON RR OR ALTON RR | | | PWRC |
| 7 | C&C | Coal & Coke Ry. | 8/1920 | | NAKINA |
| 8 | C&C | *CARTHAGE & COPENHAGEN RAILROAD | | | PWRC |
| 9 | C&C | *COAL & COKE RWY. | | | PWRC |
| 10 | C&C | *COLUMBIA & COWLITZ RAILWAY COMPANY | | | PWRC |
| 11 | C&CA | Canton & Carthage R.R. | 4/1938-4/1961 | | NAKINA |
| 12 | C&CA | Canton & Carthage R.R. | 4/38-4/61 | | NRHS |
| 13 | C&CA | CANTON & CARTHAGE RAILROAD | | | PWRC |
| 14 | C&EI | Chicago & Eastern Illinois R.R. | 10/1957-10/1966 | | NAKINA |
| 15 | C&EI | Chicago & Eastern Illinois Ry. Co. | 8/1920-/1954 | | NAKINA |
| 16 | C&EI | Chicago & Eastern Illinois Ry. Co. | 23-Jul | | NRHS |
| 17 | C&EI | Chicago & Eastern Illinois R.R. | 4/38-10/66 | | NRHS |
| 18 | C&EI | UP [MISSOURI PACIFIC] [CHICAGO & EASTERN ILLINOIS RY] | | | PWRC |
| 19 | C&G | Columbus & Greenville Ry. Co. | 7/1930-10/1966 | | NAKINA |
| 20 | C&G | Columbus & Greenville R.R. Co. | 7/1923 | | NAKINA |
| 21 | C&G | Columbus & Greenville R.R. Co. | 23-Jul | | NRHS |
| 22 | C&G | Columbus & Greenville Ry. Co. | 4/38-10/66 | | NRHS |
| 23 | C&G | COLUMBUS & GREENVILLE RY | | | PWRC |
| 24 | C&I | CAMBRIA & INDIANA RAILROAD COMPANY | | | PWRC |
| 25 | C&IC | Cedar Rapids and Iowa City Ry. | 7/1923-7/1936 | | NAKINA |
| 26 | C&IC | Cedar Rapids and Iowa City Ry. | 23-Jul | | NRHS |
| 27 | C&IC | CEDAR RAPIDS & IOWA CITY RWY. | | | PWRC |
| 28 | C&IM | Chicago & Illinois Midland Ry. | 4/1938-1/1952 | | NAKINA |
| 29 | C&IM | Chicago & Illinois Midland Ry. Co. | 8/1920-7/1936 | | NAKINA |
| 30 | C&IM | Chicago & Illinois Midland Ry. Co. | 23-Jul | | NRHS |
| 31 | C&IM | Chicago & Illinois Midland Ry. | 4/38-1/52 | | NRHS |
| 32 | C&IM | CHICAGO & MIDLAND RWY. CO. (OUT OF EXISTENCE) | | | PWRC |
| 33 | C&IW | Chicago & Illinois Western R.R. | 7/1935-1/1952 | | NAKINA |
| 34 | C&IW | Chicago & Illinois Western R.R. | 4/38-1/52 | | NRHS |
| 35 | C&IW | CHICAGO & ILLINOIS WESTERN RAILROAD | | | PWRC |
| 36 | C&L | Cornwall & Lebanon R.R. (Penna. R.R.) | 7/1930 | | NAKINA |
| 37 | C&L | Cornwall & Lebanon R.R. (Penna. R.R. System) | 8/1920-7/1923 | | NAKINA |
| 38 | C&L | Cornwall & Lebanon R.R. (Penna. R.R. System) | 23-Jul | | NRHS |
| 39 | C&L | PENNSYLVANIA RAILROAD [CORNWALL & LEBANON RAILROAD] | | | PWRC |
| 40 | C&LS | CHICAGO & LAKE SUPERIOR RWY | | | PWRC |
| 41 | C&M | Cumberland & Manchester R.R. Co. (Louisville & Nashville R.R. Co.) | 7/1930-7/1936 | | NAKINA |
| 42 | C&M | LOUISVILLE & NASHVILLE rAILROAD [CUMBERLAND & MANCHESTER RAILROAD CO.] | | | PWRC |
| 43 | C&NW | UP [CHICAGO & NORTH WESTERN TRANS CO] [CHICAGO & NORTH WESTERN RWY.] | | | PWRC |
| 44 | C&O | Chesapeake & Ohio Ry. | 4/1938-10/1966 | | NAKINA |
| 45 | C&O | Chesapeake & Ohio Ry. Co. | 7/1930-7/1936 | | NAKINA |
| 46 | C&O | C. & O. Lines (C. & O. Ry.) | 7/1923 | | NAKINA |
| 47 | C&O | C. & O. Lines (C. & O. Ry.) | 23-Jul | | NRHS |
| 48 | C&O | Chesapeake & Ohio Ry. | 4/38-10/66 | | NRHS |
| 49 | C&O | CSX TRANSPORTATION, INC. [CHESAPEAKE & OHIO RY] | | | PWRC |
| 50 | C&PA | Cumberland & Pennsylvania R.R. Co. | 8/1920-7/1936 | | NAKINA |
| 51 | C&PA | Cumberland & Pennsylvania R.R. Co. | 23-Jul | | NRHS |
| 52 | C&PA | CUMBERLAND & PENNSYLVANIA RAILROAD CO. | | | PWRC |
| 53 | C&S | Colorado & Southern Ry. | 4/1938-10/1966 | | NAKINA |
| 54 | C&S | Colorado & Southern Ry. Co. | 8/1920-7/1936 | | NAKINA |
| 55 | C&S | Colorado & Southern Ry. Co. | 23-Jul | | NRHS |
| 56 | C&S | Colorado & Southern Ry. | 4/38-10/66 | | NRHS |
| 57 | C&S | BNSF [BURLINGTON NORTHERN RAILROAD CO; COLORADO & SOUTHERN] | | | PWRC |
| 58 | C&SE | Colorado & Southeastern R.R. | 4/1938-7/1954 | | NAKINA |
| 59 | C&SE | Colorado & South-Eastern R.R. Co. | 7/1930-7/1936 | | NAKINA |
| 60 | C&SE | Colorado & Southeastern R.R. Co. | 7/1923 | | NAKINA |
| 61 | C&SE | Colorado & Southeastern R.R. Co. | 23-Jul | | NRHS |
| 62 | C&SE | Colorado & Southeastern R.R. | 4/38-1/52 | | NRHS |
| 63 | C&SE | COLORADO & SOUTHEASTERN RAILROAD CO. | | | PWRC |
| 64 | C&T | CATSKILL & TANNERSVILLE RAILROAD | | | PWRC |
| 65 | C&WC | Charleston & Western Carolina Ry. Co. (Atlantic Coast Line R.R. Co.) | 10/1966 | | NAKINA |
| 66 | C&WC | Charleston & Western Carolina R.R. | 4/1938-7/1965 | | NAKINA |
| 67 | C&WC | Charleston & Western Carolina Ry. Co. | 8/1920-7/1936 | | NAKINA |
| 68 | C&WC | Charleston & Western Carolina Ry. Co. | 23-Jul | | NRHS |
| 69 | C&WC | Charleston & Western Carolina R.R. | 4/38-7/65 | | NRHS |
| 70 | C&WC | Charleston & Western Carolina Ry. Co. (Atlantic Coast Line R.R. Co.) | Oct-66 | | NRHS |
| 71 | C&WC | ATLANTIC COAST LINE RAILROAD CO.[CHARLESTON & WESTERN CAROLINA RWY. CO.] | | | PWRC |
| 72 | C&WI | Chicago & Western Indiana R.R. Co. | 8/1920-7/1936 | | NAKINA |
| 73 | C&WI | Chicago & Western Indiana R.R. Co. | 23-Jul | | NRHS |
| 74 | C&WI | CHICAGO & WESTERN INDIANA RAILROAD CO. | | | PWRC |
