Discovery and exploration Discoveries in geography 33 History 30 Colonies 12 Indians of North America 10 European 8 Civilization 7 more ... Public opinion 7 First contact with other peoples 6 Indians 5 Transatlantic influences 5 Christianity 4 Europeans 4 Explorers 4 First contact with Europeans 4 Intellectual life 4 Territorial expansion 4 Colonization 3 Culture conflict 3 Foreign public opinion, European 3 Frontier and pioneer life 3 Indians in literature 3 Mass media 3 Migrations 3 Race relations 3 Scientific expeditions 3 Acculturation 2 American 2 American influences 2 Attitudes 2 less ...