I have some Garrens on my tree and they lived in Centralia, Illinois. Some moved to Lee Co., IL.
Did Junior have another first name? I tried Familysearch and could not find one.
There are some indexes for the Lee Co. Historical Genealogical Society in Dixon which I checked and could not find a Junior Whitrow in the pre-1940 newspaper collection and others but did not find him. I tried the 1910 and 1920 census records, still did not find him. You might contact the Society on Hennepin Avenue in Dixon. They have many records and maybe they have something about him.