| Picture File | Related File | Code |
|---|
| UFOs | | UFO |
| Uganda | | UGA |
| Uganda — Life | | UGA–Lif |
| Umbrella & parasols | | UMB |
| Uncle Sam | | UNC |
| | Allegories–Countries–United States | ALLE–Cou–US |
| | Illustrations–Flagg | ILLU–Fla |
| | Posters–Recruiting | POSTE–Rec |
| Unemployment | | UNE |
| Unemployment — Cartoons | | UNE–Car |
| Unicorns | | UNIC |
| Uniforms | | UNIF |
| | Army–France–1800s | ARMY–Fra–18 |
| | Doormen | DOORM |
| | Medicine–Surgery | MEDIC–Surg |
| | School–Japan | SCHO–Jap |
| | Servants–Maid | SERV–Mai |
| United Arab Emirates | | UNIT |
| United Nations | | UNITE |
| United Nations — Cartoons | | UNITE–Car |
| United States | | UNITED |
| United States — 1899 & earlier | | UNITED–18 |
| United States — Delaware Water Gap | UNITED–Del |
| United States — Desert | | UNITED–Des |
| United States — Ethnic types | | UNITED–eth |
| United States — Fauna & flora | | UNITED–Fau |
| United States — Industries | | UNITED–Ind |
| United States — Industries–1899 & earlier | UNITED–Ind–18 |
| United States — Lakes | | UNITED–Lak |
| United States — Lakes–1899 & earlier | UNITED–Lak–18 |
| United States — Life | | UNITED–Lif |
| United States —Life–1799 & earlier | | UNITED–Lif–17 |
| United States —Life– 1800s | | UNITED–Lif–18 |
| United States —Life–1901s | | UNITED–Lif–190 |
| United States —Life– 1910s | | UNITED–Lif–191 |
| United States —Life–1920s | | UNITED–Lif–192 |
| United States —Life–1930s | | UNITED–Lif–193 |
| United States —Life–1940s | | UNITED–Lif–194 |
| United States —Life–1950s | | UNITED–Lif–195 |
| United States —Life–1960s | | UNITED–Lif–196 |
| United States —Life–1970s | | UNITED–Lif–197 |
| United States —Life–1980s | | UNITED–Lif–198 |
| United States —Life–1990s | | UNITED–Lif–199 |
| United States —Life–2001s | | UNITED–Lif–200 |
| United States — Mississippi River | UNITED–Mis |
| United States — Mississippi River–1899 & earlier | UNITED–Mis–18 |
| United States — Mountains | | UNITED–Mou |
| United States — Mountains–1899 & earlier | UNITED–Mou–18 |
| United States — National Parks | | UNITED–Nat |
| United States — New England | | UNITED–New |
| United States — Ohio River | | UNITED–Ohi |
| United States — Palisades | | UNITED–Pal |
| United States — Rivers | | UNITED–Riv |
| United States — Rivers–1899 & earlier | UNITED–Riv–18 |
| United States — Towns & villages | UNITED–Tow |
| United States — Yellowstone | | UNITED–Yel |
| Universe | | UNIV |
| Upholstery | | UPH |
| Upper Volta | | UPP |
| | Burkina Faso | BURK |
| Uranium | | URA |
| Urination & defecation | | URI |
| Uruguay | | URU |
| Uruguay — Life | | URU–Lif |
| Uruguay — Montevideo | | URU–Mon |
| Utah | | UTA |
| Utah — 1899 & earlier | | UTA–18 |
| Utah — A–Z | | UTA–(A–Z) |
| Utah — Bryce Canyon | | UTA–Bry |
| Utah — Life | | UTA–Lif |
| Utah — Salt Lake City | | UTA–Sal |
| Utah — Salt Lake City–1899 & earlier | UTA–Sal–18 |
| Utah — Zion | | UTA–Zio |
| Utopias & lost worlds | | UTO |
