- Medical Services Administration16
- Medical Services Bureau4
- Medicine and Sanitation Committee1
- Medicine and Surgery Bureau1,262
- Medicine and Surgery Bureau (Navy Department)11
- Medicine and Surgery Bureau (Navy)1,098
- Medicine and Surgery, Bureau of6
- Mediterranean Fruit Fly Board1
- Members of Congress, Select Committee to Investigate Alleged Charges Against1
- Memorial Bridge Commission1
- Merchant Marine Commission11
- Merchant Marine Commission (Congress)4
- Merchant Marine and Fisheries Committee932
- Merchant Marine and Fisheries Committee, House1,255
- Merchant Marine and Fisheries Committee, Senate1
- Merchant Marine and Fisheries, Committee on the40
- Merchant Marine, Radio, and Fisheries Committee, House57
- Mesa Verde National Park7
- Meses Bureau19
- Mexican Boundary Survey4