The Post Exchange
Camp followers, vici, sutlers, vivandieres, chuckwagons, exchanges, or whatever you want to call them, they have been a part of military life since the dawn of history. In WWII, the United States Army Post Exchange (PX) system had PXs in 62 countries on 6 continents, ranging from the smallest Pacific Island to downtown London and San Francisco.
Note: The PX is also the best place to send the new guy to stock up on some flight lines, prop wash, and a box of grid squares to get them out of your hair.