The United States enters both world wars immediately

How would both world wars change if the United States joined at the beginning?

Earlier US entry would add Allied manpower and production. The answer develops the World War II possibilities of earlier deployments to France and French North Africa.

Earlier American entry would give the Allies much more manpower and production from the outset. The answer develops the World War II case most specifically. US forces could reach France during the phoney war, where their positioning might change the 1940 campaign. Landings in French North Africa could also occur sooner. The corresponding World War I operations are not worked through.