973 - United States 851
327 - International relations 70
970 - History of North America 58
971 - Canada 44
976 - South central United States 41
972 - Middle America; Mexico 39
320 - Political science 37
978 - Western United States 30
917 - Geography of & travel in North America 28
301 - Sociology & anthropology 25
330 - Economics 25
940 - History of Europe 24
975 - Southeastern United States 23
977 - North central United States 23
979 - Great Basin & Pacific Slope region 20
329 - [Unassigned] 17
974 - Northeastern United States 17
325 - International migration & colonization 15
353 - Specific fields of public administration 15
338 - Production 11
942 - England & Wales 8
322 - Relation of state to organized groups 7
326 - Slavery & emancipation 6
342 - Constitutional & administrative law 6
816 - American letters in English 6
309 - [Unassigned] 5
323 - Civil & political rights 5
810 - American literature in English 4
980 - History of South America 4
071 - Newspapers in North America 3
266 - Missions 3
321 - Systems of governments & states 3
331 - Labor economics 3
332 - Financial economics 3
944 - France & Monaco 3
959 - Southeast Asia 3
191 - Philosophy of United States & Canada 2
328 - The legislative process 2
333 - Economics of land & energy 2
335 - Socialism & related systems 2
347 - Civil procedure & courts 2
509 - Historical, geographic & persons treatment 2
813 - American fiction in English 2
818 - American miscellaneous writings 2
907 - Education, research & related topics 2
909 - World history 2
910 - Geography & travel 2
951 - China & adjacent areas 2
141 - Idealism & related systems 1
144 - Humanism & related systems 1
285 - Presbyterian, Reformed & Congregational 1
289 - Other denominations & sects 1
299 - Religions not provided for elsewhere 1
300 - Social sciences 1
317 - General statistics of North America 1
324 - The political process 1
336 - Public finance 1
340 - Law 1
345 - Criminal law 1
352 - General considerations of public administration 1
355 - Military science 1
361 - Social problems & social welfare in general 1
363 - Other social problems & services 1
380 - Commerce, communications & transportation 1
386 - Inland waterway & ferry transportation 1
636 - Animal husbandry 1
639 - Hunting, fishing & conservation 1
720 - Architecture 1
759 - Historical, geographic & persons treatment 1
770 - Photography, photographs & computer art 1
814 - American essays in English 1
824 - English essays 1
848 - French miscellaneous writings 1
900 - History & geography 1
901 - Philosophy & theory 1
911 - Historical geography 1
913 - Geography of & travel in ancient world 1
920 - Biography, genealogy & insignia 1
935 - Mesopotamia & Iranian Plateau to 637 1
943 - Central Europe; Germany 1
948 - Scandinavia 1
952 - Japan 1
962 - Egypt & Sudan 1