Subject headings are specific vocabulary that the Library of Congress assigns to published material. You can search I-Share for books and other materials related to historical research by subject heading. General subject headings in history follow a specific pattern: Place name -- Subdivision -- Time period.
Place names:
Can be names of countries, regions, states, or cities.
Subdivisions:
Describe the particular emphasis of the book.
Time period:
Refers to the years covered by the book. Time period designations vary according to place name and are not included for all headings.
The following examples illustrate possible subject searches for various aspects of late 19-century history:
| Place Name | Subdivision | Time Period |
| Pennsylvania-- | History-- | Civil War, 1861-1865 |
| United States-- | History-- | |
| Intellectual Life-- | 1865-1898 | |
| Social Conditions-- | 1865-1918 | |
| Emigration and Immigration-- | 1865-1918 | |
| Politics and Government-- | 1865-1900 | |
| Foreign Relations-- | 1865-1898 |
Sometimes, however, you may find an alternate pattern, with a specific subject listed first. For example:
| Subject | Place Name | Subdivision | Time Period |
| Women-- | New York-- | History-- | 19th Century |
| Middle Classes-- | United States-- | History-- | 20th Century |
| Jews-- | United States-- | History-- | 20th Century |
| African-Americans-- | Southern State-- | History-- | |
| Family-- | United States-- | History-- |
For more information, consult the Library of Congress Authorities online (see below) or the five printed volumes in Reference, Library of Congress Subject Headings(LCSH), which contains the subject headings used in BobCat and other library catalogs. Look under the place name or subject to see the appropriate subdivisions and time periods.
