Frontier and pioneer life History 35 Indians of North America 17 Territorial expansion 11 Race relations 10 Wars 10 Colonies 6 more ... First contact with other peoples 6 Ethnic relations 5 Government relations 5 Politics and government 5 Social aspects 5 African Americans 4 Social conditions 4 African American pioneers 3 Imperialism 3 African American soldiers 2 African American troops 2 Attitudes 2 Borderlands 2 Civilization 2 Colonization 2 Frontier thesis 2 Fur trade 2 Generals 2 Geography 2 Land tenure 2 National characteristics, American 2 Political culture 2 Administration 1 less ...