History 1,538 Biography 760 World War, 1939-1945 727 Politics and government 586 Campaigns 342 Juvenile literature 225 Foreign relations 150 United States 142 Description and travel 129 World War, 1914-1918 108 Social conditions 92 Malaysia 83 Aerial operations 82 Vietnamese Conflict, 1961-1975 77 Civilization 76 Presidents 69 History, Military 66 Personal narratives, American 66 Economic conditions 63 World war, 1939-1945 61 Social life and customs 59 Pictorial works 56 Politicians 55 Personal narratives 52 Terrorism 51 Naval operations 50 World War 49 Great Britain 47 Geography 45 Iraq War, 2003 45