History 1,733 Geology 417 Indians of North America 406 Maps 383 Flood insurance 349 Politics and government 343 Housing 319 Agriculture 300 Education 282 Roads 281 Statistics 271 Description and travel 263 Law and legislation 253 Insurance, Flood 249 Railroads 228 Real property 224 Buildings, structures, etc 221 Social life and customs 216 Frontier and pioneer life 214 Economic conditions 209 Regional planning 208 Maps, Topographic 205 Buildings 202 City planning 192 Soils 185 Population 180 Finance 176 Land use 165 Environmental aspects 161 Legislative amendments 158 Study and teaching 158 Landowners 149 Water quality 149 Law 145 Soil surveys 145 Geology, Stratigraphic 144 Groundwater 140 Planning 140 Social conditions 137 Navigation improvements 136 Ojibwa Indians 136 Rivers, creeks, streams, etc 135 Legislative resolutions 133 Indian reservations 130 Women 124 Curricula 120 Mortgage banks 118 Farm life 112 Outdoor recreation 111 Periodicals 111 Lakes 109 Federal aid to transportation 108 Library buildings 106 Water 104 Economic aspects 101 Universities and colleges 101 Antiquities 100 Research 99 Forests and forestry 96 Biography 95 Pollution 88 Trade-unions 88 Church history 86 Families 86 Claims 85 Harbors 85 Flood forecasting 84 Land grants 84 General 83 Mortgage loans 80 Stream measurements 80 Land titles 79 Taxation 79 Fiction 78 Transportation 78 Indians 77 Lead mines and mining 75 Registers of births, etc 75 Timber 75 Government relations 74 Mines and mineral resources 74 Water-supply 74 Alphabets 73 Family 73 Wages 73 Harbors and ports 72 Public lands 71 Employment 69 Libraries 69 Indian allotments 67 Legal status, laws, etc 67 African Americans 66 Evaluation 66 Hydrographic surveying 66 Natural history 66 Artists' books 65 Hydrology 65 Indian treaties 65 Land tenure 64 Collective labor agreements 62