Hi I have the book "The Shorter Family, England, America and Africa in the History of a family" by Avlward Shorter and Maggie Price Taylor. I was surprise that I did not find your William Shorter born c. 1790 in/near Shipbourne, Kent. The only places in Kent were Bybrook, Hothfield, Great Chart and Westwell per this book. Sir Robert Walpole's wife was Catherine Shorter b. abt 1682. Of course, this is all much erlier than your c1790 birth.