After finding secondary sources in the catalog, you'll have a good sense of the keywords to use for your topic.
Now, try one of your searches from before, but limit the publication box to your time period.
For example, I'm interested in 19th century school houses. I revisit my earlier search of ("school house*" OR "schoolhouse*") AND American
I then narrow the publication field to 1800-1899. I find 66 books about my topic published during that time period, making them primary sources. There are also 136 newspaper and magazine articles, also all primary sources.
Use The main library catalog to find primary sources by limiting to publication date or using the subject headings below.
Example: "College of William and Mary" limited to 1800-1850
Use Subject Terms to find historic materials in the collection. NOTE: DO NOT LIMIT PUBLICATION DATE RANGE FOR THESE SEARCHES
Unofficial terms that are not Library of Congress official terms but may be helpful