Through my cousin in Phoenix, we now know Joseph was in the Revolutionary War. His rank was Private. He was 3rd Class in the 3rd Battalion in the Company of Captain William McCall. He served from 1780 to 1783. The Lieutenancy is in Bedford, PA.
From Dictionary.com: lieu·ten·an·cy [loo-ten-uhn-see] 1. the office, authority, incumbency, or jurisdiction of a lieutenant.
With this information, we can probably assume Joseph was probably born before 1765.