While it sometimes seems as if Primary Sources just can't be found, especially if you're researching a topic that might not have many sources available, on the other hand it is true that Primary Sources can be everywhere! Places you can find sources include:
Your own home. Does your family keep photo albums or scrapbooks of documents about you or your family, including family photographs, marriage and birth certificates or old financial documents? These are Primary Sources.
Your town or city hall or municipal office. Towns and cities generate and store many materials that document its businesses and citizens, including land transfer documents, voters registrations, and information about changes to town or city laws.
Historical monuments and markers
Many archives and libraries are making copies of the Primary Sources they hold available online. They are usually available in online exhibits, digital projects, in their blogs, or on Flickr. The following websites are great places for online Primary Sources and often include resources for educators.
The Library of Congress has a huge collection of primary sources and can be accessed at https://www.loc.gov/.
The National Archives has a large number of records at https://www.archives.gov/. Access historical documents at https://www.archives.gov/historical-docs.
For local history, visit the Oklahoma Historical Society at https://www.okhistory.org/. Review the index at https://www.okhistory.org/research/index.
Oklahoma State University has a number of digital collections at https://library.okstate.edu/search-and-find/collections/digital-collections/.