During WWII, why were most all of the radio crystal manufacturers based in the Mid West? Think about it!
BINGO! With communications the heart of war, most of the crystal and radio manufactures were in the middle of the country, out of range from attack. Ain't ya glad you learned something today!
Pete - Are you sure about this? Several of the radio manufacturers that I could think of (Collins - Iowa, Motorola - Illinois, Hammarlund - Ohio, etc) went into business in the 1910-30's period, pre-WWII. So their location was established beforehand. Some (like Drake - Ohio) were started during WWII in order to meet the war demand, but the location then could have been as much to do with supplier logistics during that period as for safety.
Because if you look under your Kilt and you have a Quarter-Pounder, you are a Mc Donald, not a Mac Donald!