- Brown, Treacy & Sperry Co. (Saint Paul, Minn.)1
- Bureau of Transportation Statistics1
- Burritt, Elijah H. (Elijah Hinsdale), 1794-18381
- Burrus, R. F.1
- Butler, Ethan E.1
- C.M. Foote & Co. (Minneapolis, Minn.)1
- C.S. Hammond & Company1
- C.S. Mendenhall (Firm)1
- Cai, Meijun1
- Cannon, William F.1
- Canoe Country Outfitters1
- Carlson, D. R. (David Roy)1
- Carlson, Kristin1
- Clark, C. W. (Engineer)1
- Cleveland, H. W. S. (Horace William Shaler), 1814-19001
- Colby, Charles Galusha, 1830-1866?1
- Colton, J. H. (Joseph Hutchins), 1800-18931
- Columbia Planograph Co.1
- Comber, W. G.1
- Cook, R.1