??John Cleves Symmes?? (1742 -1814) was a delegate to the Continental Congress from New Jersey, and later a pioneer in the United States Northwest Territory.? He was also the father-in-law of United States President William Henry Harrison. He was the son of the Rev. Timothy Symmes (1715 -1756) and Mary Cleves (died c. 1746) of Suffolk County, New York on Long Island.? John was born in Riverhead, New York on July 21, 1742.