William Estill is the son of William Estell and Martha Jennings. He may have been born in Barren Co., KY. instead of Fleming Co., KY., which is still to be determined. He married Mary "Polly" Williams on Dec. 25, 1817 in Bath Co., KY. They had 14 children: Sarah Williams, Elizabeth Emma, Martha Jennings, James Williams, Samuel, William John, Issac Berry, Robert Hale, Hannah W., Joseph William, David Foster, Mary Dulcena, Jacob, and Lydia Jane. William Estill was a member of Cumberland Presbyterian Church, was a veteran of the "War of 1812", and moved to Illinois in 1824.