"Primary sources are the raw materials of history — original documents and objects which were created at the time under study. They are different from secondary sources, accounts or interpretations of events created by someone without firsthand experience. " http://www.loc.gov/teachers/usingprimarysources/index.html
To locate primary sources, use filters in the databases to limit results to primary sources, letters, speeches, political, government & court documents, etc. Also try adding the search term "primary sources" to an Internet search. The websites are good options to locate primary sources.