Encyclopedias, Almanacs, Transcripts, and Maps
- Union Navy
- Union of Brest (1596)
- Union of Comoros
- Union of Right Forces
- Union of Sovereign States
- Union of Soviet Writers
- Union of Struggle for The Emancipation of Labor
- Union Treaty
- Unions Plan Merger
- Unit Cohesion
- Unitarianism and Universalism
- United Automobile Workers of America
- United Fruit Company Strike
- United Kingdom
- United Kingdom African Dependencies
- United Kingdom American Dependencies
- United Mine Workers Strike
- United Nations Charter
- United Nations Depository Libraries
- United Nations Headquarters