Imperialism 54 Territorial expansion History 42 Foreign relations 29 Political aspects 11 Politics and government 8 Race relations 7 Racism 7 National characteristics, American 5 Political culture 5 Social aspects 5 Democracy 4 Nationalism 4 Philosophy 4 Civilization 3 Commerce 3 Economic aspects 3 Globalization 3 Indians of North America 3 Liberty 3 Slavery 3 Territories and possessions 3 African Americans 2 Annexation to the United States 2 Capitalism 2 Collective memory 2 Colonial question 2 Colonies 2 Comparative civilization 2 Cotton growing 2