Trade cards, also known as advertising cards were popular collectibles in the latter half of the 19th century. They advertised a wide range of manufactured goods and often contain a separate advertisement for the local seller of the product.

After his retirement as Chairman of Humanities in 1968, John Adams became part-time university archivist for San Diego State College. John and his wife Jane donated generously to the university. Their donations consisted of books, postcards, ephemera, and manuscripts.