Creator
- Clarke, Frank Wigglesworth, 1847-19311
- Clason, George S. (George Samuel), 1874-19571
- Cleanliness Institute1
- Collins Printing House1
- Colton, J.W. (Firm)1
- Columbia University1
- Comar, C. L.1
- Consolidated Edison Company of New York, inc.1
- Constable1
- Cooley, Le Roy C. (Le Roy Clark), 1833-19161
- Cornish, George Anthony, 1901-19891
- Cramp, Arthur J. (Arthur Joseph), 1872-1
- Cranston & Stowe1
- Crittenden, C. H.1
- Croft, Terrell, 1880-19671
- Crosby Lockwood and Son1
- Croscup & Sterling1
- Damon, Samuel Reed1
- De Ong, E. R. (Elmer Ralph), 1882-19661
- Delaware River Chemical Works1