There are many websites dedicated to describing the history of occupational therapy, some with international perspective, which you can find with a quick Google search. As you search for information, be sure to investigate the author of the information, and look for sites that cite their sources.
Your online access to AJOT, whether through your student AOTA membership or through the library, only goes back to 1980. We have access all the way back to the original 1947 issue in print or on microfilm, which you can request at the Library Service Desk at the front of the library. Fortunately, AJOT is also indexed all the way back to 1947 through PsycInfo, so that provides another opportunity to do historical research.