I did some further research on the charcoal drawing in Sullivan's Tavern in Dekalb, Illinois, done by Grant Wood. The way they had it worded on the menu made me believe that Grant Wood did it overseas in World War I.
I found out that Wood joined the Army even though he was exempted from the draft and never went to Europe until after the war and as a civilian. His artistic abilities were used by the Army to come up with camouflage for artillery pieces.
He did train at Camp Dodge outside of Des Moines, Iowa, which served as a regional training center. This is most likely where Earl Sullivan, Sr. met him and where the drawing was done. I could find no information on Earl Sullivan's life.
More information is on this past week's entries at my history blog (http://cootershistorything.blogspot.com)
Anyway, a bit of interesting stuff for you folks driving along the Lincoln Highway in Illinois.
A Beer and a Drawing. --RoadDog