Final answer:
Popular action films of the 1940s were mainly patriotic war films like 'The Fighting Seabees' and 'Back to Bataan' with John Wayne, which mirrored World War II sentiments and aimed to boost troop morale.
Step-by-step explanation:
The most popular action films during the 1940s were often patriotic in nature, reflecting the sentiment of World War II. Movies like The Fighting Seabees and Back to Bataan, both featuring John Wayne, were among the favorites that filled theaters. While these films depicted the battles against the Axis powers, they also served to inspire and glorify American troops. During a time when national pride and the war effort were predominant themes in American society, Hollywood played a vital role in both entertaining and bolstering the morale of the American public.