William Harry Mosby was born 24 January 1898 in Sioux City, Woodbury Co., Iowa, to Harry E. and Anastasia E. (Skorunka) Mosby.By 1930 he was in Chicago working as a commercial artist.He lived with his aunt Helen Ethel Mosby, a spinster.Before 1940 he married Alice _unknown_.
There is an article on Wikipedia that describes his training in Belgium and gives some additional information on his commerical work.
He is a descendant of John and Anne (McCreary) Moore.
From some posts online, I believe that he had at least one child, a son William Harry Mosby, Jr.However, he must have been born after 1940 since in the 1940 census, he and Alice have no children.
A 1951 article in the Wilmette paper indicates that some of his works were on display there when a new wing opened; it also lists Alice Mosby as one of the artists being featured.
I have not yet learned the exact date of his death, but he died in Wilmette, Cook Co., IL.