The first four are of American troops during WWI. No patches, distinctive hats, puttees (like an ace bandage wrapped around the shoe tops and lower leg). Tho others are from WWII, one of an infantry division (91st?) corporal/technician on a what looks to be a plow horse (the 91st had a tough time). Another is an ambulance crew wearing "dungarees" (cotton fatigues), black boots, and patrol caps, which looks to me like post-WWII stateside training. The ambulance is one of the standard types, and vehicle had their USA serial number prominently displayed back then. The tourist on the balcony is wearing the Service Forces patch, so the war is probably nearly over; he looks to be in Italy or on the Riviera. The last two are P-38 fighters being unloaded by British workers, judging by their clothes.

Most of the plane fuselages look more like P38s to me.

It also looks like the first four were taken with a different camera or developed differently from the rest, so all those from the horse + thatched cottage onwards are presumably world war 2 (the house looks like it would belong in England, and the number plate fragment on the US army van also looks British, so I'd guess the latter 5 relate to US army personnel in world war 2, stationed in England).