- Interstate Commission on the Potomac River Basin1
- Interstate Migration of Destitute Citizens, Select Committee to Investigate, House8
- Interstate and Foreign Commerce Committee3,416
- Interstate and Foreign Commerce Committee, House2,497
- Interstate and Foreign Commerce Committee, Senate236
- Interstate and Foreign Commerce, Committee on173
- Invalid Cessions Committee204
- Invalid Pensions Committee4,346
- Invalid Pensions Committee, House201
- Invalid Pensions, Committee on2,964
- Investigation Bureau40
- Investigation Division8
- Irrigation Board1
- Irrigation Committee1
- Irrigation Committee (Senate)9
- Irrigation and Reclamation Committee94
- Irrigation and Reclamation Committee, House252
- Irrigation and Reclamation Committee, Senate233
- Irrigation and Reclamation of Arid Lands Committee48
- Irrigation and Reclamation of Arid Lands, Committee on7