Thanks for the reply. I came across Alice's site a few years ago and we traded emails, but she was not able to help me.
I am trying to find the parents of my 3rd great-grandfather, Francis Asbury Preston, b 1832 near Nicholasville, KY.
He appears on the 1850 Jessamine Co, KY census on the same page with Lewis Preston, Milton Preston and Berryman Preston. I found a marriage consent dated 9-Jan-1868, signed by Francis and witnessed by Gratten Preston. By a process of elimination, I think his father may have been your Lewis Preston.
This has been a real brick wall for me. I assume your grandmother's notes didn't list any possible children of Lewis other than those on Alice's site?