Most academic libraries have collections of primary sources that history students can use in their research. Often, these are collections of sources about the same event or group of people. These books are usually cataloged with the subject heading "Sources." Locating books with the subject heading "Sources" AND a subject heading for the event or concept you are researching will usually find lots of primary source material.
This search in JaySearch (Advanced):
Finds great primary sources, like these: