The collection includes subject files, correspondence, scrapbooks, articles, lectures, notes, drafts of works by Williams, drafts of works by others, photographs, programs and other papers relating to the history of foreign settlement in Japan and its influence on, and adaptation to, Japanese society. The papers also relate to Japanese culture, individual expatriate residents, other foreigners, foreign businesses, communities and clubs in Japan until the 1980s. These papers contain the primary material used by Williams in his many published books and articles.