History 69 Juvenile literature 56 United States 34 Sources 22 Terrorism 16 Biography 14 Politics and government 13 World War, 1939-1945 13 Foreign relations 10 Social conditions 9 Trials, litigation, etc 8 Holocaust, Jewish (1939-1945) 7 September 11 Terrorist Attacks, 2001 7 Social aspects 7 Civil rights 6 Prevention 6 Campaigns 5 African Americans 4 Civil War, 1861-1865 4 Cold War 4 Concentration camps 4 Race relations 4 Speeches, addresses, etc., American 4 War crime trials 4 World politics 4 Antislavery movements 3 Capital punishment 3 Encyclopedias 3 Ethnic relations 3 Europe 3