Scope and Contents The John and Jane Adams Postcard Collection consists of over 100 years of history and communication through postcards. The postcards are diverse in size, format, and subject. The collection contains more than 4,500 postcards of San Diego County, and 8,500 postcards representing parts of the state of California and the development of California. Individual states in the U.S. as well as other countries of the world also have categories in the collection....