I have been interested in American Folk art since the '60's. I had attended a
wonderful exhibit at the Whitney Museum in New York City. I believe the
Whitney's were extensive collectors of the Americana. At the time, I
purchases several books from the Museum. I would try to get their website and
find out if they still have these publications.
People who like American Antiques collect the folk art. Try your antiques
book sections of the bookstores and the libraries. Antiques dealers are also
very knowledgeable. The Metropolitan Museum in N.Y. has an American wing and
many fine examples of the Limner Painters. <A HREF="www.metmuseum.org">Met
Hope I've helped.