My father retired from the Army when I was in first grade. He began working for the Department of Defense as a civilian. He was a tech rep with headquarters in Detroit. That is where all the tanks and jeeps were built. You cannot recall a tank from overseas when something goes wrong with it. So my father would go to Detroit for a few months and be trained and then he would go to Europe, or Vietnam, or Iran - and go from base to base teaching the people in the motor pools how to fix the problem.  I lived in Detroit 8 different times!