The Life Magazine Image Archive on Google includes a large number of photos of Missouri persons, cities, towns, and other places. The following search terms will call up hundreds of Missouri-related images:
Harry S. Truman
Louis Cardinals (use Louis to filter out photos of religious figures)
T. S. Eliot
Thomas Hart Benton
University of Missouri
These examples should give you an idea of the many possibilities available when it comes to searching this images treasure trove:
http://www.google.com(select Images in top row on screen).