Topical subject terms, geographical place names, occupations, and forms of material represented in finding aids. Subjects are selected from controlled lists of words and phrases used by the Library of Congress.
U
- Ulithi (Micronesia).
- Ultrasonics.
- Undercover operations--United States.
- Underwater exploration.
- Unemployed--United States.
- Unemployment.
- Unemployment--United States.
- Union organizers.
- Unionists (United States Civil War).
- Unitarianism.
- United States--Altitudes.
- United States--Appropriations and expenditures.
- United States--Armed forces.
- United States--Armed Forces--African American officers.
- United States--Armed Forces--African Americans.
- United States--Armed Forces--Appropriations and expenditures.
- United States--Armed Forces--Armored troops.
- United States--Armed Forces--Drill and tactics.
- United States--Armed Forces--History.
- United States--Armed Forces--Intelligence specialists--Education.
- United States--Armed Forces--Minorities.
- United States--Armed Forces--Officers.
- United States--Armed Forces--Officers--Correspondence.
- United States--Armed Forces--Officers--Obituaries.
- United States--Armed Forces--Pay, allowances, etc.
- United States--Armed Forces--Periodicals.
- United States--Armed Forces--Philippines.
- United States--Armed Forces--Recruiting, enlistment, etc.
- United States--Armed Forces--Reorganization.
- United States--Armed Forces--Supplies and stores.
- United States--Biography.
- United States--Biography--Encyclopedias.
- United States--Boundaries.
- United States--Boundaries--Canada.
- United States--Boundaries--Florida.
- United States--Boundaries--Mexico.
- United States--Capital and capitol.
- United States--Census, 1890.
- United States--Census, 1900.
- United States--Census, 1910.
- United States--Census, 1920.
- United States--Census, 1930.
- United States--Centennial celebrations, etc.
- United States--Civilization.
- United States--Civilization--Study and teaching.
- United States--Claims.
- United States--Claims vs. France.
- United States--Claims vs. Mexico.
- United States--Claims vs. Spain.
- United States--Commerce.
- United States--Commerce--Brazil.
- United States--Commerce--Canada.
- United States--Commerce--China.
- United States--Commerce--Cuba.
- United States--Commerce--Europe.
- United States--Commerce--France.
- United States--Commerce--Great Britain.
- United States--Commerce--History--19th century.
- United States--Commerce--History--20th century.
- United States--Commerce--Iran.
- United States--Commerce--Iraq.
- United States--Commerce--Japan.
- United States--Commerce--Latin America.
- United States--Commerce--Russia.
- United States--Commerce--South America.
- United States--Commerce--Soviet Union.
- United States--Commercial policy.
- United States--Commercial treaties.
- United States--Defenses.
- United States--Description and travel.
- United States--Description and travel--Bibliography.
- United States--Discovery and exploration.
- United States--Economic conditions.
- United States--Economic conditions--1865-1918.
- United States--Economic conditions--1918-1945.
- United States--Economic conditions--1945-.
- United States--Economic conditions--1971-1981.
- United States--Economic conditions--1981-2001.
- United States--Economic conditions--19th century.
- United States--Economic conditions--20th century.
- United States--Economic conditions--To 1865.
- United States--Economic policy.
- United States--Economic policy--1933-1945.
- United States--Economic policy--1945-1960.
- United States--Economic policy--1971-1981.
- United States--Economic policy--1981-1993.
- United States--Economic policy--19th century.
- United States--Economic policy--20th century.
- United States--Economic policy--21st century.
- United States--Economic policy--To 1933.
- United States--Emigration and immigration.
- United States--Ethnic relations.
- United States--Foreign economic relations.
- United States--Foreign relations.
- United States--Foreign relations--1775-1783.
- United States--Foreign relations--1783-1865.
- United States--Foreign relations--1789-1797.
- United States--Foreign relations--1789-1809.
- United States--Foreign relations--1829-1847.
- United States--Foreign relations--1861-1865.
- United States--Foreign relations--1865-.
- United States--Foreign relations--1865-1898.
- United States--Foreign relations--1865-1921.
- United States--Foreign relations--1897-1901.
- United States--Foreign relations--1901-1909.
- United States--Foreign relations--1913-1921.
- United States--Foreign relations--1921-1923.
- United States--Foreign relations--1923-1929.
- United States--Foreign relations--1933-1945.
- United States--Foreign relations--1945-.
- United States--Foreign relations--1945-1953.
- United States--Foreign relations--1945-1989.
- United States--Foreign relations--1961-1963.
- United States--Foreign relations--1977-1981.
- United States--Foreign relations--1989-.
- United States--Foreign relations--2001-.
- United States--Foreign relations--20th century.
- United States--Foreign relations--21st century.
- United States--Foreign relations--Africa.
- United States--Foreign relations--Africa, North.
- United States--Foreign relations--Algeria.
- United States--Foreign relations--Argentina.
- United States--Foreign relations--Asia.
- United States--Foreign relations--Australia.
- United States--Foreign relations--Austria.
- United States--Foreign relations--Azerbaijan. .
- United States--Foreign relations--Belgium.
- United States--Foreign relations--Bosnia and Hercegovina.
- United States--Foreign relations--Brazil.
- United States--Foreign relations--Canada.
- United States--Foreign relations--Cape Verde.
- United States--Foreign relations--Catholic Church.
- United States--Foreign relations--Central America.
- United States--Foreign relations--Chechni︠a︡ (Russia) .
- United States--Foreign relations--Chile.
- United States--Foreign relations--China.
- United States--Foreign relations--Colombia.
- United States--Foreign relations--Cuba.
- United States--Foreign relations--Czechoslovakia.
- United States--Foreign relations--Denmark.
- United States--Foreign relations--Dominican Republic.
- United States--Foreign relations--East Asia.
- United States--Foreign relations--Egypt.
- United States--Foreign relations--Europe.
- United States--Foreign relations--European Union countries.
- United States--Foreign relations--Former communist countries.
- United States--Foreign relations--France.
- United States--Foreign relations--Germany.
- United States--Foreign relations--Great Britain.
- United States--Foreign relations--Greece.
- United States--Foreign relations--Haiti.
- United States--Foreign relations--Hawaii.
- United States--Foreign relations--Honduras.
- United States--Foreign relations--India.
- United States--Foreign relations--Indonesia.
- United States--Foreign relations--Iran.
- United States--Foreign relations--Iraq.
- United States--Foreign relations--Ireland.
- United States--Foreign relations--Israel.
- United States--Foreign relations--Italy.
- United States--Foreign relations--Japan.
- United States--Foreign relations--Korea.
- United States--Foreign relations--Korea (North).
- United States--Foreign relations--Kosovo (Republic) .
- United States--Foreign relations--Laos.
- United States--Foreign relations--Latin America.
- United States--Foreign relations--Lebanon.
- United States--Foreign relations--Libya.
- United States--Foreign relations--Luxembourg.
- United States--Foreign relations--Mexico.
- United States--Foreign relations--Micronesia (Federated States).
- United States--Foreign relations--Middle East.
- United States--Foreign relations--Morocco.
- United States--Foreign relations--Mozambique.
- United States--Foreign relations--Netherlands.
- United States--Foreign relations--New Zealand.
- United States--Foreign relations--Nicaragua.
- United States--Foreign relations--Norway.
- United States--Foreign relations--Oman.
- United States--Foreign relations--Palestine.
- United States--Foreign relations--Panama.
- United States--Foreign relations--Persian Gulf.
- United States--Foreign relations--Persian Gulf Region. .
- United States--Foreign relations--Peru.
- United States--Foreign relations--Philippines.
- United States--Foreign relations--Poland.
- United States--Foreign relations--Portugal.
- United States--Foreign relations--Prussia (Germany).
- United States--Foreign relations--Puerto Rico.
- United States--Foreign relations--Romania.
- United States--Foreign relations--Russia.
- United States--Foreign relations--Saudia Arabia.
- United States--Foreign relations--South Africa.
- United States--Foreign relations--South America.
- United States--Foreign relations--South Asia.
- United States--Foreign relations--Soviet Union.
- United States--Foreign relations--Spain.
- United States--Foreign relations--Thailand.
- United States--Foreign relations--Treaties.
- United States--Foreign relations--Tunisia.
- United States--Foreign relations--Turkey.
- United States--Foreign relations--Uruguay.
- United States--Foreign relations--Venezuela.
- United States--Foreign relations--Vietnam.
- United States--Foreign relations--Yugoslavia.
- United States--Genealogy.
- United States--Historiography.
- United States--History.
- United States--History--1783-1865.
- United States--History--1815-1861.
- United States--History--1849-1877.
- United States--History--1865-.
- United States--History--1865-1898.
- United States--History--1865-1921.
- United States--History--1933-1945.
- United States--History--1945-1953.
- United States--History--19th century.
- United States--History--20th century.
- United States--History--Bibliography.
- United States--History--Civil War, 1861-1865.
- United States--History--Civil War, 1861-1865--African Americans.
- United States--History--Civil War, 1861-1865--Anecdotes.
- United States--History--Civil War, 1861-1865--Art and the war.
- United States--History--Civil War, 1861-1865--Artillery operations.
- United States--History--Civil War, 1861-1865--Autographs.
- United States--History--Civil War, 1861-1865--Blockades.
- United States--History--Civil War, 1861-1865--Campaigns.
- United States--History--Civil War, 1861-1865--Casualties.
- United States--History--Civil War, 1861-1865--Causes.
- United States--History--Civil War, 1861-1865--Cavalry operations.
- United States--History--Civil War, 1861-1865--Censorship.
- United States--History--Civil War, 1861-1865--Civilian relief.
- United States--History--Civil War, 1861-1865--Claims.
- United States--History--Civil War, 1861-1865--Confiscations and contributions.
- United States--History--Civil War, 1861-1865--Economic aspects.
- United States--History--Civil War, 1861-1865--Engineering and construction.
- United States--History--Civil War, 1861-1865--Finance.
- United States--History--Civil War, 1861-1865--Foreign public opinion.
- United States--History--Civil War, 1861-1865--Health aspects.
- United States--History--Civil War, 1861-1865--Hospitals.
- United States--History--Civil War, 1861-1865--Journalists.
- United States--History--Civil War, 1861-1865--Maps.
- United States--History--Civil War, 1861-1865--Medical care.
- United States--History--Civil War, 1861-1865--Military intelligence.
- United States--History--Civil War, 1861-1865--Military personnel.
- United States--History--Civil War, 1861-1865--Monuments.
- United States--History--Civil War, 1861-1865--Naval operations.
- United States--History--Civil War, 1861-1865--Naval operations, Confederate.
- United States--History--Civil War, 1861-1865--Participation, African American.
- United States--History--Civil War, 1861-1865--Peace.
- United States--History--Civil war, 1861-1865--Periodicals.
- United States--History--Civil War, 1861-1865--Personal narratives.
- United States--History--Civil War, 1861-1865--Personal narratives, Confederate.
- United States--History--Civil War, 1861-1865--Prisoners and prisons.
- United States--History--Civil War, 1861-1865--Psychological aspects.
- United States--History--Civil War, 1861-1865--Public opinion,.
- United States--History--Civil War, 1861-1865--Refugees.
- United States--History--Civil War, 1861-1865--Religious aspects.
- United States--History--Civil War, 1861-1865--Secret service.
- United States--History--Civil War, 1861-1865--Songs & music.
- United States--History--Civil War, 1861-1865--Songs and music.
- United States--History--Civil War, 1861-1865--Technology.
- United States--History--Civil War, 1861-1865--Veterans.
- United States--History--Civil War, 1861-1865--War work.
- United States--History--Civil War, 1861-1865--Women.
- United States--History--Colonial period, ca. 1600-1775.
- United States--History--Confederation, 1783-1789.
- United States--History--Constitutional period, 1789-1809.
- United States--History--French and Indian War, 1754-1763.
- United States--History--French and Indian War, 1754-1763--Campaigns.
- United States--History--French and Indian War, 1755-1763.
- United States--History--French and Indian War, 1755-1763--British forces.
- United States--History, Local.
- United States--History, Military.
- United States--History, Military--21st century.
- United States--History, Military--To 1900.
- United States--History, Naval.
- United States--History, Naval--19th century.
- United States--History, Naval--20th century.
- United States--History--Revolution, 1775-1783.
- United States--History--Revolution, 1775-1783--Amphibious operations.
- United States--History--Revolution, 1775-1783--British forces.
- United States--History--Revolution, 1775-1783--Campaigns.
- United States--History--Revolution, 1775-1783--Claims.
- United States--History--Revolution, 1775-1783--Committees of correspondence.
- United States--History--Revolution, 1775-1783--Committees of safety.
- United States--History--Revolution, 1775-1783--Cryptography.
- United States--History--Revolution, 1775-1783--Equipment and supplies.
- United States--History--Revolution, 1775-1783--Finance.
- United States--History--Revolution, 1775-1783--Naval operations.
- United States--History--Revolution, 1775-1783--Participation, African American.
- United States--History--Revolution, 1775-1783--Participation, French.
- United States--History--Revolution, 1775-1783--Participation, German.
- United States--History--Revolution, 1775-1783--Participation, Spanish.
- United States--History--Revolution, 1775-1783--Peace.
- United States--History--Revolution, 1775-1783--Personal narratives.
- United States--History--Revolution, 1775-1783--Prisoners and prisons.
- United States--History--Revolution, 1775-1783--Prizes, etc.
- United States--History--Revolution, 1775-1783--Secret service.
- United States--History--Sources.
- United States--History--Study and teaching.
- United States--History--Tripolitan War, 1801-1805.
- United States--History--Tripolitan War, 1801-1805--Naval operations.
- United States--History--War of 1812.
- United States--History--War of 1812--Campaigns.
- United States--History--War of 1812--Destruction and pillage.
- United States--History--War of 1812--Naval operations.
- United States--History--War of 1812--Naval operations, British.
- United States--History--War of 1812--Participation, British.
- United States--Intellectual life.
- United States--Intellectual life--1865-1918.
- United States--Intellectual life--19th century.
- United States--Intellectual life--20th century.
- United States--Military policy.
- United States--Military policy--20th century.
- United States--Militia--Periodicals.
- United States--National Guard.
- United States--National security.
- United States--Officials and employees.
- United States--Officials and employees--Interviews.
- United States--Officials and employees--Selection and appointment.
- United States--Politics and government.
- United States--Politics and government--1775-1783.
- United States--Politics and government--1783-1789.
- United States--Politics and government--1783-1809.
- United States--Politics and government--1783-1865.
- United States--Politics and government--1789-1797.
- United States--Politics and government--1789-1809.
- United States--Politics and government--1789-1815.
- United States--Politics and government--1801-1809.
- United States--Politics and government--1809-1817.
- United States--Politics and government--1815-1861.
- United States--Politics and government--1817-1825.
- United States--Politics and government--1829-1837.
- United States--Politics and government--1837-1841.
- United States--Politics and government--1841-1845.
- United States--Politics and government--1845-1849.
- United States--Politics and government--1845-1861.
- United States--Politics and government--1849-1853.
- United States--Politics and government--1849-1877.
- United States--Politics and government--1853-1857.
- United States--Politics and government--1857-1861.
- United States--Politics and government--1861-1865.
- United States--Politics and government--1865-1869.
- United States--Politics and government--1865-1877.
- United States--Politics and government--1865-1900.
- United States--Politics and government--1865-1933.
- United States--Politics and government--1869-1877.
- United States--Politics and government--1877-1881.
- United States--Politics and government--1881-1885.
- United States--Politics and government--1885-1889.
- United States--Politics and government--1889-1893.
- United States--Politics and government--1893-1897.
- United States--Politics and government--1897-1901.
- United States--Politics and government--18th century.
- United States--Politics and government--1901-1909.
- United States--Politics and government--1901-1953.
- United States--Politics and government--1909-1913.
- United States--Politics and government--1913-1921.
- United States--Politics and government--1919-1933.
- United States--Politics and government--1921-1923.
- United States--Politics and government--1923-1929.
- United States--Politics and government--1929-1933.
- United States--Politics and government--1933-1945.
- United States--Politics and government--1933-1953.
- United States--Politics and government--1945-.
- United States--Politics and government--1945-1953.
- United States--Politics and government--1945-1989.
- United States--Politics and government--1946-.
- United States--Politics and government--1953-1961.
- United States--Politics and government--1961-1963.
- United States--Politics and government--1963-1969.
- United States--Politics and government--1969-1974.
- United States--Politics and government--1974-1977.
- United States--Politics and government--1977-1981.
- United States--Politics and government--1981-1989.
- United States--Politics and government--1989-.
- United States--Politics and government--1993-2001.
- United States--Politics and government--19th century.
- United States--Politics and government--2001-2009.
- United States--Politics and government--20th century.
- United States--Politics and government--21st century.
- United States--Politics and government--Caricatures and cartoons.
- United States--Politics and government--Dictionaries.
- United States--Politics and government--Press coverage.
- United States--Politics and government--Statistics.
- United States--Politics and government--To 1775.
- United States--Population.
- United States--Race relations.
- United States--Relations--Japan.
- United States--Religion.
- United States--Religion--19th century.
- United States--Religious life and customs.
- United States--Social conditions.
- United States--Social conditions--1865-1918.
- United States--Social conditions--1933-1945.
- United States--Social conditions--1945-.
- United States--Social conditions--1960-1980.
- United States--Social conditions--20th century.
- United States--Social life and customs.
- United States--Social life and customs--1865-1918.
- United States--Social life and customs--1918-1945.
- United States--Social life and customs--19th century.
- United States--Social life and customs--20th century.
- United States--Social policy.
- United States--Social policy--20th century.
- United States--Strategic aspects.
- United States--Surveys.
- United States--Territorial expansion.
- United States--Territories and possessions.
- United States--Trials, litigation, etc.
- Universities & colleges--United States--1890-1940.
- Universities and colleges.
- Universities and colleges--Administration.
- Universities and colleges--Alabama--Tuskegee.
- Universities and colleges--California.
- Universities and colleges--Connecticut--New Haven.
- Universities and colleges--France.
- Universities and colleges--Illinois.
- Universities and colleges--Illinois--Chicago.
- Universities and colleges--Indiana--Greencastle.
- Universities and colleges--Kansas.
- Universities and colleges--Maine--Brunswick.
- Universities and colleges--Maryland--Chestertown.
- Universities and colleges--Massachusetts.
- Universities and colleges--Massachusetts--Amherst.
- Universities and colleges--Massachusetts--Cambridge.
- Universities and colleges--New Jersey.
- Universities and colleges--New Jersey--Princeton.
- Universities and colleges--New York (State).
- Universities and colleges--New York (State)--Clinton.
- Universities and colleges--New York (State)--Ithaca.
- Universities and colleges--New York (State)--New York.
- Universities and colleges--New York--West Point.
- Universities and colleges--Ohio.
- Universities and colleges--Ontario--London.
- Universities and colleges--Pennsylvania.
- Universities and colleges--Pennsylvania--Pittsburgh.
- Universities and colleges--South Carolina.
- Universities and colleges--Soviet Union.
- Universities and colleges--Vermont.
- Universities and colleges--Vermont--Bennington.
- Universities and colleges--Vermont--Northfield.
- Universities and colleges--Virginia.
- Universities and colleges--Virginia--Charlottesville.
- Universities and colleges--Virginia--Hampton.
- Universities and colleges--Washington (D.C.).
- Universities and colleges--Wisconsin.
- Universities and colleges--Wisconsin--Madison.
- Upper class--United States.
- Upper Marlboro (Md.)--Commerce.
- Uranium.
- Uranium enrichment.
- Urban beautification.
- Urban beautification--United States.
- Urban folklore--United States.
- Urban policy.
- Urban policy--United States.
- Urban policy--Washington (D.C.).
- Urban renewal.
- Urban schools--United States.
- Uruguay--Commerce.
- Uruguay--Description and travel.
- Uruguay--Foreign relations--United States.
- U.S. states--History.
- Ushers.
- Utah--Description and travel.
- Utah--Discovery and exploration.
- Utah--History.
- Utah--Politics and government.
- Utah--Social life and customs.
- Ute Indians.
- Utopias--Russia.