John is the son on Jonathan Warner, Sr and Mary Griffin Warner. Jonathan moved with his parents at an early age to Pittsford. He served several times as a member of the State Legislature and held other civil and military offices, including that of Captain.
It is said that upon arriving at the Delaware River the night before the Battle of Princeton, Washington wanted a boat from the opposite shore. It was Jonathan Sr. who volunteered to swim the stream to get it. Washington patted him on the shoulder and said "Brave fellow" and sent him to get a dry suit of clothes.
Anna Ripley Warner