Below are a few relevant Library of Congress Subject Headings. These can help you in finding basic guides, manuals and historical methodology books in our Local Catalog.
The difference between these and "tags" you may have experience is that the Library of Congress controls what terms, spelling, etc. are used. This "controlled vocabulary" helps organize words and phrases in predictable ways.
Think about the searching for "civil war" as a keyword. What you would find would be more would include concept of "civil war" in various countries. To find information related only to the United States civil war, it would be more efficient to use a subject heading like
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