When I was in boot camp in 1945, our DI instilled in us the correct way to mention the name of one of the Corps greatest leaders. That being Lt Gen John Archer Lejeune and he emphasized that the General and his family called it as Luh-Jern.
Well I called his name and the base Luh-jern for the next 22 years. During the 60s I found out that the civilian populace and the media in the Jacksonville area started calling it again as La-joon.