How did the American military improve in World War 2 from world World War 1?

The number one difference of the American military in WWII was the American rifle. All other countries were using bolt action weapons as the standard infantry weapon basically the same weapon from WWI, America had developed the M-1 Garand a semi-automatic weapon. Two other areas that American military improved upon from WWI to WWII and that was 1. the strategic use of tanks to support infantry and 2. the strategic use of airpower to support landings, infantry movements etc.