
The Library of Congress Classification System is used to organize books and materials in libraries according to 21 branches of knowledge. The 21 categories (labeled A-Z except I, O, W, X, and Y) are further divided by adding one or two additional letters and a set of numbers. This system is in use at the Library of Congress and at most academic and research libraries in the United States.
This alphabetical list should help you determine where particular subjects fall within the LC classification system.
| Accounting | HF |
| African-Americans | E 184.5-185.98 |
| Agriculture | S |
| American history | E |
| American history--African-Americans | E 184.5-185.98 |
| American history--Asian-Americans | E 184.06 |
| American history--Discovery of America | E 101-135 |
| American history--Hispanic-Americans | E 184 |
| American history--Native Americans | E 51-99 |
| American history--United States (general) | E 151 |
| Anthropology | GN |
| Archaeology | CC |
| Architecture | NA |
| Art | N |
| Asian-Americans | E 184.06 |
| Astronomy | QB |
| Athletics | GV 561-1197 |
| Bacteriology | QR |
| Bible | BS |
| Biography (general) | CT |
| Biology | QH |
| Botany | QK |
| Buddhism | BQ |
| Business Administration | HC-HG |
| Business Law | K |
| Catholic Church | BX 800-4795 |
| Celtic languages and literature | PC 1201-3029 |
| Chemistry | QD |
| Christian Church history | BR |
| Christian denominations | BX |
| Christianity (general) | BR |
| Classical languages and literature | PA |
| Commerce | HF |
| Community Education | LC |
| Computer Industry | HC-HD |
| Computers; Computer Science | QA76 |
| Counseling | BF; HQ 636-637 |
| Dance | GV 1580-1799 |
| Decorative arts | NK |
| Design | NC |
| Drama | PN 6110-6120 |
| Drawing | NC |
| Economics | H-HJ |
| Education | L |
| Encyclopedias | AE |
| Engineering | T |
| English | PE, PR, and PS |
| English language | PE |
| Esthetics | BH |
| Ethics | BJ |
| Fine Arts | N |
| Folklore | GR |
| Games | GV 1200-1570 |
| Genealogy | CS |
| General works | A |
| Geography | G |
| Geology | QE |
| Germanic languages | PD |
| Health science | RA |
| Hispanic-Americans | E 184 |
| History (general) | D |
| History--Africa | DT |
| History--America (general) | E |
| History--Asia | DS |
| History--Ancient history, classical antiquity | DE |
| History--Canada | F 1001-1140 |
| History--Central America | F 1421-1577 |
| History--Europe | D |
| History--France | DC |
| History--Germany | DD |
| History--Great Britain | DA |
| History--Ireland | DA 900-975 |
| History--Latin America | F 1401-1419 |
| History--Mexico | F 1201-1392 |
| History--North America | E - F 1140 |
| History--Russia | DK |
| History--South America | F 2201-3799 |
| History--United States (local) | F 1-970 |
| Human anatomy | QM |
| Islam | BP |
| Journalism | PN |
| Judaism | BM |
| Languages | P-PM |
| Languages--English | PE |
| Languages--French | PC 2001-3767 |
| Languages--German | PF 3001-5999 |
| Languages--Greek | PA 227-1179 |
| Languages--Latin | PA 2001-2995 |
| Languages--Spanish | PC 4000 |
| Law | K |
| Law--United States | KF |
| Library science | Z |
| Literature | PN-PZ |
| Literature--American | PS |
| Literature--Classical | PA |
| Literature--English | PR |
| Literature--French | PQ |
| Literature--German | PT |
| Literature--Spanish | PQ |
| Logic | BC |
| Management | HC-HD |
| Marketing | EF |
| Mathematics | QA |
| Medicine | R |
| Metaphysics | BD 95-131 |
| Microbiology | QR |
| Military science | U |
| Modern European Languages (general) | PB |
| Music | M |
| Music, literature of | ML |
| Musical instruction and study | MT |
| Mythology | BL |
| Native American history | E 51-99 |
| Naval science | V |
| Painting | ND |
| Philosophy | B-BD |
| Photography | TR |
| Physical education | GV |
| Physics | QC |
| Physiology | QP |
| Plant culture | SB |
| Political science | J |
| Political science--United States | JK |
| Psychology | BF |
| Quantitative methods | QA 76 |
| Religion | BL-BX |
| Religions | BL |
| Roman Catholic Church | BX800 |
| Romance languages | PC |
| Scandinavian languages | PD1501-5929 |
| Science | Q |
| Sculpture | NB |
| Sociology | HM-HX |
| Speech | PN |
| Sports | GV 561-1197 |
| Statistics | HA |
| Technology | T |
| Telecommunications | TK 5100s |
| Theology | BT-BX |
| Yearbooks | AY |
| Zoology | QL |