I got that information from Familysearch.com. It is possible that a church record could be located for their marriage. Not many actual marriage records survive from that time period.Try the state archives. They would most likely have one if it is available.
I found this on a family tree.
Mary Curtis Born: 16 Jun 1799 in Stafford, [county], Virginia, USA Died: 15 Jan 1880 in Brokensword, Crawford, Ohio, USA Edit Marriage: 24 Oct 1817 in Stafford, [county], Virginia, USA
Try Crawford county courthouse for a death record for both of them. Try RAOGK.com for a lookup there.