Who's the dim-witted one on the far left? With his hat he looks like Gomer Pyle
Of course, Gomer (played by Jim Nabors, RIP) was a true American, and went on to (fictionally) serve his country in the Marines (the TV show "Gomer Pyle, U.S.M.C."), so I don't mean to disparage a real fictional patriot...
Interesting fact about "Gomer Pyle, U.S.M.C.":
Actual filming was done at the U. S. Marine Corps Recruit Depot (MCRD) San Diego, California 92140 - pictured in the photograph from left to right: Gomer Pyle (Jim Nabors); USMC Representative / MCRD Technical On-Site Advisor (Drill Instructor Edwin J. Kues, USMC); and, Gunnery Sergeant Vince Carter (Frank Sutton). This photo was taken in between actual filming of the comedy production at MCRD San Diego, California in 1964.