OK, if we want to be pedantic about this, Von Braun and his scientists came up with the first INS towards the end of WWII. It was however amazingly innacurate and certainly not good enough for point to point navigation. On the first flight of the Lincoln Labs instrument they managed to fly across the continental USA and their error on arrival was only 150m.
I would not want to go to the moon using a Von Braun system for navigation.