Which war-time innovation fundamentally transformed the U.S. military's Post Exchange (PX) system into the modern retail operation we recognize today?

The Post Exchange (PX) system represents one of the most significant retail innovations in military history, evolving from simple sutlers' tents to modern department stores serving military personnel worldwide. This specialized retail ecosystem has shaped military life, morale, and even influenced civilian retail practices. Test your knowledge about this unique military retail institution that has supported troops for generations.

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

World War II's introduction of the Army Exchange Service, centralizing operations across global theaters
Vietnam War's implementation of the 'combat PX' bringing retail operations directly to forward operating bases
Spanish-American War's establishment of permanent PX buildings replacing temporary sutler tents
Cold War development of AAFES (Army & Air Force Exchange Service) merging separate branch retail operations