Conversation so far:
Where did William F. Buckley Jr. go to school?
Alma mater. Yale University.
Where did William F. Buckley Jr. go to high school?
Millbrook School in Millbrook, New York
When did William F. Buckley Jr. join the military?
1944

Question: How long did he serve in the military?
Self-contained rewrite: How long did William F. Buckley Jr. serve in the military?