Basically the title sums up the whole subject, but let me get a little deeper.

Amelia Earhart, Wiley Post, and a number of other aviators received the Distinguished Flying Cross before the DFC finally became a strictly military-only medal.

If Wiley Post or Amelia Earhart had later joined the U.S. Military, what would the protocol be about their pre-military medals? Also, Earhart received a French Legion of Honor after her solo crossing of the Atlantic despite not being in the military. Would a foreign award work differently at all?