Walt was born in Chicago in 1901.
when Walt was 17 in 1918, WWI broke out and he really wanted to be a Red Cross ambulance driver in France. But he had to be 18 to do that. Luckily Walts birth certificate was written in pencil so he changed his birthdate from 1901 to 1900 and applied for the Red Cross. They of course accepted him thinking that he was 18.
While driving ambulances in France, he took up smoking and drawing on the ambulance itself.
I have more facts that I will post later. You can also pitch in and post any facts you find interesting about Walt.