Did you know there is an Institute of American Deltiology? It is in Myerstown, Pennsylvania (about an hours drive from Harrisburg).
The I.A.D. was started by Donald Brown and contains over 1 million postcards. Housed in an old general store, the I.A.D. was established to act as a library, research center and gallery with a focus is on North American postcards. Included in the collection are resources supporting the collection, such as books, periodicals, slides and news bulletins.