History 11,404 Politics and government 3,263 Description and travel 1,849 Geology 1,807 Indians of North America 1,449 Frontier and pioneer life 1,382 Social life and customs 1,358 Mexican Americans 1,329 Law and legislation 1,220 Antiquities 1,120 Economic conditions 887 Housing 872 African Americans 868 Annexation to the United States 863 Biography 826 Manners and customs 797 Soil surveys 739 Social conditions 729 Soils 724 Finance 717 Agriculture 699 Political science 692 Maps 678 Geology, Stratigraphic 670 Statistics 664 Education 651 Music 618 Excavations (Archaeology) 595 Travel 578 Roads 573 Slavery 560 Mortgage banks 559 Groundwater 551 Law 533 Periodicals 505 Women 483 Presidents 477 General 475 Paleontology 475 Boundaries 474 Histoire 473 Ranch life 470 Water-supply 470 Race relations 469 Popular music 449 International relations 437 Petroleum 434 Emigration and immigration 429 Environmental aspects 423 Real property 419 Railroads 415 Population 399 HISTORY 397 Economic history 389 Mortgage loans 387 Fiction 386 Harbors 384 Families 373 Motion pictures 373 Food 358 Buildings, structures, etc 347 War 342 Politics, Practical 338 Cowboys 336 Mexicans 336 State & Local 335 Americanisms 334 Slang 334 Language and languages 333 Soldiers 333 Public buildings 331 Wages 331 Water quality 331 Patriotism 330 History and criticism 329 Current events 327 Dollar 327 Foreign relations 327 Navigation 317 Folklore 308 Art 304 City planning 298 Cooking 296 Bridges 294 Civil rights 293 Murder 293 Petroleum industry and trade 286 Cooking, American 283 Land grants 282 Water resources development 281 Buildings 279 Sources 279 Public lands 278 Social aspects 278 Economic aspects 276 Mexican War, 1846-1848 264 Universities and colleges 261 Missions 259 Pollution 257 Architecture 255