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- Unexploded Ordnance Caucus (2005–)
- Upper Mississippi River Basin Task Force (1997–)
- U.S.-Afghan Caucus (2006(?)–)
- U.S.-China Working Group (2006(?)–)
- U.S.-Mongolia Friendship Caucus (2006(?)–)
- U.S.-New Zealand Congressional Caucus (2006(?)–)
Read more about this topic: Caucuses Of The United States Congress