Tariff 57 Protectionism 36 History 25 Canals 22 Politics and government 17 Free trade and protection 14 Protection 14 more ... African Americans 12 Colonization 12 Railroads 12 Public works 11 Causes 9 Nullification (States' rights) 9 Political parties 9 Yellow fever 9 Banks and banking 8 Description and travel 8 Economic conditions 8 Plague 8 Agriculture 7 Free trade 7 Poor 6 Women 6 Commercial policy 5 Education 5 Employment 5 Foreign relations 5 Clergy 4 Commerce 4 Histoire 4 Poles in the United States 4 Polish people 4 States' rights (American politics) 4 Yellow Fever 4 Catholics 3 Charities 3 Church history 3 Disease Outbreaks 3 Economics 3 Emigration and immigration 3 less ...