Included in this promotion of WWII here in the United States would be the "advertisements" of specific household items and other arenas.
One specific introduction would be Westinghouse's "We Can Do It" poster that presented Rosie the Riveter (The Saturday Evening Post cover, circa 1943). This introduction of women promoting the war became a type of promotion in multiple facets. The Liberty Girl of The Saturday Evening Post (1943) also offered the woman as the "jack of all trades" in doing her part to promote the war effort.
There was the feeling that pervaded throughout popular culture that the war effort was a noble one and a cause that was pure. Hollywood rallied around this by ensuring that its stars were available for service or to entertain the troops. Hollywood's rendition of the war through its films also ensured that there was a complete sanitizing of the war in delivering the message to the people that the United States stood on the side of right and moral superiority through its depiction of the war. Actors and actresses were told to make sure nothing controversial was said and all of them went along with the script. In the end, Hollywood, in the absence of television, was seen as the popular conduit to ensure that the public was completely in support of the war effort.
There were all sorts of ways in which popular culture promoted the war effort at home during World War II.
There were many movies made about the war. These typically showed the Americans and their allies fighting valiantly against the evil enemy. One example of this is the movie Bataan.
Similarly, you can even see support for the war effort in cartoons. Both Popeye the Sailor and Bugs Bunny had cartoons in which they directly fought against the Japanese. In various Bugs Bunny cartoons there are references to the need to do things like avoiding unnecessary traveling so as to help with the war effort.