In 1942, the War Department established the Armed Forces Radio Service (AFRS). Early programs included the program Jubilee which ran until 1952, Command Performance which ran until 1951, G.I. Journal which ran to 1945 and Mail Call which ran until 1949. They brought news and entertainment to the front lines in the worst of times in WWII, Korea, and Vietnam. Today they're heard in Bosnia, Iraq, Afghanistan anywhere the military goes.
Their roots began before 1942 in a couple different corners of the world. There was PCAN at Fort Clayton in the Panama Canal Zone and at lesser known station in in the Hawaii, Philippines, and a station known alternately as KRB, GIN, GAB in Sitka, Alaska. Some military men started what were essentially pirate radio stations. I know this assessment is unpopular, but there were licenses to be gotten, and they widely did not. This site lists off some early AFRS staff at PCAN. It is somtimes referred to as Albrook, as that is the name of the airfield there.
The AFRS station in Kodiak is usually credited with being the first station in the AFRS network. Of the early three or four stations they can brag that they've stayed on the air continually. Within 5 years of KRB, there were 16 AFRS stations in Alaska. Bear in mind they didn't become a state until 1959. These were not FCC licensed stations. These were remote military outposts. Radioheritage.com has a lot of information on these here.Also notable was KGEI which operated out of Redwood City California, near San Francisco. They operated direct short-wave broadcasts to the Philippines where American Military relayed it. The station was built around 1940 by general Electric. Previously it operated as W6XBE during the San Francisco Worlds Fair. It was bought in 1959 and operated by The Far East Broadcasting Co. (FEBC) then closed in 1995. More here
AFRN still operates today. It is interesting that over the last 70 years it's remained vaguely commercial, a contrast to the obvious propaganda of VOA.