- Revision of Laws, Special Joint Committee on (Congress)3
- Revolutionary Claims Committee2
- Rifle Practice Promotion Board2
- Rifle Practice Promotion Board (War Department)1
- Rivers and Harbors Board243
- Rivers and Harbors Board (Engineer Department, War Department)1
- Rivers and Harbors Committee370
- Rivers and Harbors Committee, House590
- Rivers and Harbors, Board of Engineers for (Engineer Department, War Department)1
- Rivers and Harbors, Committee on10
- Road Inquiry Office63
- Road Material Laboratory1
- Roads Committee27
- Roads Committee, House87
- Roanoke Colony Commission2
- Roberts, Brigham H., Special Committee on1
- Rochambeau Statue Committee1
- Rock Creek Park, Joint Select Committee on Addition to (Congress)2
- Rock Creek Valley Parkway Commission1
- Rock Creek and Potomac Parkway Commission4