As with primary sources, the key to finding secondary sources is deciding which keywords work best.
Use the worksheet to work out keywords for your topic.
We have a number of excellent databases listed in our history resources library page, but for this class America: History and Life is the best starting point.
There are books, sometimes called reference works or tertiary texts, that are about the study of history itself.
These Historiographical texts - the history of history - can provide insights into what historians have said about your topic.