Most of the early to mid-40s were dominated by WW2 and marked the beginning of the baby-boomer years. Many new advancements in technology were made during wartime, but also other events that marked the 40s.
Captain America Comic Book
The first-ever Captain America comic book was published and the cover had the Captain punching real-life Nazi villain Adolf Hitler right in the face. The first issue was published under “Timely Comics” which would later become “Marvel Comics.” Created by Jack Kirby, he would also go on to create "Silver Surfer", "Thor", and "Hulk", amongst many others.