World War I draft registration card, George F. Oak, 12 Sep 1918, Skowhegan.
Image · dated 12 Sep 1918 · source: WWI draft registrations, FamilySearch image.

How it is shown: Complete image as saved; no crop, no retouch, no search highlight.
Keep in mind: Registration only, not service. His own statement of birth is 23 June 1873.