The author of this propaganda justifies America’s participation in the war by saying that, like the Revolutionary War in 1778, America is fighting for justice and liberty. Its presence in the war has a cause, and the cause is a good one. I believe the motive of the artist/author was to increase support and recruitment for the American participation.
The artist draws upon the revolutionary war to compare the motive of American action. The picture shows that although time has changed, America’s willingness to fight for what’s right has not. Technological advances changed how war is fought, but the cause has not.