Territorial expansion History 35 Foreign relations 12 Frontier and pioneer life 11 Politics and government 9 Expansion territoriale 6 Slavery 6 more ... Colonial question 5 Histoire 5 Indians of North America 5 Government relations 4 Discovery and exploration 3 Eastern question (Far East) 3 Explorers 3 Extension to the territories 3 Historical geography 3 Imperialism 3 Mexican War, 1846-1848 3 Public opinion 3 Race relations 3 Causes 2 Colonization 2 Diplomatic relations 2 Discoveries in geography 2 Filibusters 2 Immigration and emigration 2 Insular possessions 2 Land settlement 2 Louisiana Purchase 2 Politique et gouvernement 2 Presidents 2 Public lands 2 Spanish-American War, 1898 2 20e s. (1ère moitié) 1 Américain d'origine hispano-américaine (peuple) 1 Américains d'origine latino-américaine 1 Annexation 1 Annexation to Soviet Union 1 Annexation to the United States 1 Anti-imperialist movements 1 less ...