Subject headings are controlled vocabulary terms used to consistently lead you to relevant information.
These terms are used by the library catalog and WorldCat databases. Some periodical databases also use these terms.

Southern states -- Politics and government
Southern states -- Economic conditions
Southern states -- Elections

Each of the subdivisions can also be used with specific states:
[State] -- Politics and government

Sometimes the geographic term is the second element of the heading:

Political parties -- Southern States (or specific state)
Political culture -- Southern States (or specific state)
Politicians -- Southern States (or specific state)

Videos, DVDs & Music

On the library home page, you can select the "Find Videos" tab to search exclusively for video. You will also find videos in the library catalog as you search for books and other materials. To limit your search to videos in the library catalog, go to the "Advanced Keyword Search" option and use the "Material type" box to select videorecordings. Or, after performing a search, click the "Modify Search" or "Limit/Sort" button and select the material type videorecordings option there. You can also browse the documentary section by the same call number ranges mentioned under Books above.