Duane Hanson is a good example of the fusion of "Pop" and realism in American art.
He synthesises the common (c.f the "Ashcan"artists) subject, with a slavishly realistic approach to the subject (c.f Warhol's celebrities). A great discussion of this is to be found on the following:
http://www.tfaoi.com/aa/4aa/4aa439.htm
This is a discussion by a Gallery that features his work, discusses his techniques (good for 3.1 "Style") and also talks about him in a social/artistic context (3.6 "Context").
An explanation of the term "heartland"- this means the very centre of a country or more specifically, culture. That is something that represents the very best examples (epitome) of that culture.