Often, the best work arises from close engagement with a primary source. As you read, you'll think of questions or begin to shape an argument. The hard part is to find a primary source that addresses the broad general area of interest. Here are some strategies for finding primary sources:
Some primary sources are collected in books, which you can find the library catalog.
To find the papers of an individual, search for that person as an author, e.g. jackson, andrew
To find the records of an organization or government body, use the name of the organization as an author e.g. United States. Dept. of State
Include one of these words as a keyword or a subject:
If you find something that looks useful, look at the detailed view of the catalog record and try to identify the "subject" assigned. For many topics in history, there's an official term used in all Anglo-American library catalogs, like:
To find works published in a particular time and place, explore the search options. It is usually possible to limit your search by date, language, or location of publication.