I suspect your Jonathan's Surname maybe Wilhelm.My Family surname is Helm. The area where I was born and raised, people pronounced it as "Hellum" After several years of searching for a connection to the famous Helm family of Hardin County Kentucky, I found out the Surname was Wilhelm. It was changed to Helm circa 1870 after my ggg grandfather died as a Union soldier in 1862. William Hellums could have been Wilhelm???The Hart County KY Census of 1850 listed a George W Helm was actually George Wilhelm.Hope this gives you a lead to identify Jonathan!