William Morris

I'm looking for information about William Morris. He was born in New York in 1783. His son's biography says he came to Iowa in 1836. I know he was married to Catharine Cothran and Martha Wright. His son, Van Rensselaer, was my great great grandfather. I haven't been able to find anything about him from birth - 1836. He's on the 1850 census in Lee County, Iowa and then he disappears again. Has anyone found him in your lineage? Thanks!