Marion would be Marion Twp Sanilac Co, including Deckerville. Check out Sandusky District Library they have added their entire obituary and cemetery database for Sanilac County Area plus more at their site, free and searchable from Home. Check out Downing Cemetery, Wheatland Township (across the Rd. from Marion Twp), there are several French's buried in the middle of the Cemetery next to the Morden Plot. Checking SeekingMichigan.org another free site, I found a death certificate for Aaron French b. 26 Oct. 1839 Can, d. 18 Jun 1917 age 77y 7m 23d. s/o Charles H. French b. New Hampshire & Nancy Smith, b. Canada. Informant was Nelson French of Beaverton, MI. Aaron is buried in Croswell Cemetery, Croswelle, MI. Aaron died in Buel Twp, Sanilac County which is West of Croswell, MI. Some of those families migrated north from Worth & Buel Townships.