- C. B Comstock (Cyrus Ballou), 1831-1910. (1)
- C. C. Reinhardt & Co (Baltimore City, Maryland) (1)
- C. F. Anderson Co. Inc (Minneapolis, Minnesota) (1)
- C. J. Hibbard (1)
- C. J. Hibbard & Company (1)
- C. Schepeler (Göttingen, Germany) (1)
- C. Smith & Son (1)
- C. W. Alban (St. Louis, Missouri) (1)
- C.B. Graham's Lithography (1)
- C.B. Photo Service (1)
- C.H. Johnston Associates (1)
- C.I. Hood & Co. (Lowell, Mass.) (1)
- C.M. Foote & Co. (1)
- C.M. Foote & Co. (Minneapolis, Minn.) (1)
- C.S. Hammond & Company (2)
- CAP-FILL Products Co., Inc (Ardmore, Pennsylvania) (1)
- CEA (Draughtsman) (1)
- CUNA Mutual Insurance Society (1)
- Cadden, Joseph (1)
- Caddy, John (2)