- Panama Canal Tolls and Vessel Measurement Rules Committee1
- Panama Canal, Board of Consulting Engineers for (Isthmian Canal Commission, War Department)4
- Panama Canal, Washington Office10
- Panama Fortification Board1
- Panama Railroad Commissioner, Special2
- Panama Railroad Commissioner, Special (War Department)1
- Panama Railroad Company16
- Pant Industry, Soils, and Agricultural Engineering Bureau7
- Parcel Post, General, Joint Committee to Investigate2
- Paris, Exposition Universelle, 19006
- Parole Boards10
- Passport Control Division12
- Passport Division2
- Past American Union17
- Patent Office9,397
- Patent Office (Interior Department)60
- Patent Office, Commerce Dept.9
- Patent and Trade-Mark Laws Commission2
- Patent and Trademark Office18
- Patents Commitee293