1941 Captain America Comics #37
Alex Schomburg was a powerhouse artist that worked well over 70 years as a paid artist in everything from comic books to magazines and print ads until his death in the late 90s. Alex is considered one of the most popular cover artists during the Golden Age of Comics and when he left that genera for the Sci-Fi magazine one he brought his skill and vision to a whole new audience and wowed them as well. I admit that Alex's Captain America and All-Winners covers is how I see my WWWII wargaming and is some of the best comic art I have seen to date. Do some Google-Fu and see some of his other works because it is legion in number and all fantastic.
One of the best, ever.
1943 All-Select Comics #1