The us government made broad use of propaganda during world war ii to caution people about war.
build support for the war effort.
spread false information about the germans.
keep people employed.

I think the US use propaganda in order to gain support from neutral countries.With the help their resources, they were able to come up with creative political cartoons. Most of these political cartoon may seem harmless. However, they denote strong political meanings from the government

Answer to your question is Build support for the war effort. U.S. Entered the world war II after Japan Attacked Pearl Harbor. Becaus U.S. government needed support for the war effort. there were a lot of movies and animations which draw attention to the neccesity of U.S involment in the war and also the importance of allied victory.