- Crater Lake National Park8
- Crater Lake National Park (Interior Department)2
- Crime, Organized, in Interstate Commerce, Special Committee to Investigate, Senate7
- Crime, Select Committee on31
- Criminal Identification Bureau2
- Criminal Law, Select Committee to Investigate Administration of, by Federal Officials1
- Criminal and Penal Laws, Commission to Revise and Codify3
- Crop Estimates Bureau130
- Crop Insurance Select Committee1
- Crop-Estimating Board1
- Crow, Flathead, etc., Indian Commission2
- Cuba Postal Committee1
- Cuba Posts Department1
- Cuba Relations Committee2
- Cuba and Porto Rico Special Commissioner10
- Cuban Census Office5
- Currency, Division of1
- Customs Bureau548
- Customs Congress of American Republics, 19031
- Customs Court155