I would guess the Mid West would be an area best known for casserole type dishes. Most if not all of regional cooking came from anywhere on the East Coast originally, with the exception of the South West.
Most of our regional so called offerings all came from Europe and adapted on the treck west to what may be available in that area.
A very good refrence cook book you may enjoy is The Settelment cook book.
Many recepies from that area. Chow Jim