Conversation so far:
Where did Pat Robertson go to school?
Pat Robertson attended the preparatory McDonogh School, The McCallie School, Washington and Lee University, Yale Law School, and The Biblical Seminary in New York.
Did Pat Robertson go to college?
The colleges Pat Robertson attended are Washington and Lee University, Yale Law School, and The Biblical Seminary in New York.
What did Pat Robertson study in school?
Pat Robertson received a B.A. in History, a law degree, and a Master of Divinity degree.

Question: When did he enter the military?
Self-contained rewrite: When did Pat Robertson enter the military?