By 1942, the United States was firmly entrenched in World War II. Mrs. Miniver was greenlit in 1940, well before the United States had dreamed of entering the war. MGM had carefully written the script to reflect the United States' neutrality, but as production wound on, it became more and more certain that the United States would enter the war on the side of the allies. By the time the film was released, the United States was firmly involved in the war and Mrs. Miniver was definitely what the U.S. audiences were looking for.
