Hasbro issued these 4 sets without boxes.
As far as I know, they were supposed to be sold online only.
The idea was to honour the 4 main conflict of the 20th century the USA were involved in.
The serie pictured here is complete.
First is WWI 94th Aero Squadron in 1917. "Aviator Ace".
Second is WWII Staff Sgt. 17th Airborne Belgium 1944.
Third is Korean War Private 1st class 7th Inf. Div. 1951. "Korea Private".
Fourth is Vietnam War 1st Air Cavalry 1970.
The 4 diorama bases can be clipped together.