History 21,568 Description and travel 5,575 Politics and government 5,242 Social life and customs 3,393 Social conditions 2,929 Antiquities 1,709 Race relations 1,615 more ... Frontier and pioneer life 1,524 Civilization 1,496 African Americans 1,406 Economic conditions 1,381 Foreign relations 1,374 Indians of North America 1,161 Indians of South America 926 Indians of Mexico 889 Discovery and exploration 778 Ethnic relations 737 Mayas 714 Relations 698 Travel 600 Social aspects 572 Colonies 543 Sources 513 Religion 485 Jews 459 Intellectual life 447 Missions 447 Pictorial works 427 Historic buildings 410 Civil rights 409 less ...