Conversation so far:
What branch of the military did Ed McMahon serve in?
he still had to finish his two years of college before applying for Marine Corps flight training.
Did he serve in any wars?
He was a Marine Corps flight instructor in F4U Corsairs for two years, finally being ordered to the Pacific fleet in 1945.
Was he wounded in service?
his orders were canceled after the atomic bomb was dropped on Hiroshima and Nagasaki.

Question: What rank did he achieve by the end of his service?
Self-contained rewrite: What rank did Ed McMahon achieve by the end of his service?