Thank you for posting this message naming the children of Thomas Hill. I'm researching the line of Charles Hickock, husband of Mariah Hill, and got no further than her father's name. Now, thanks to you, I was able to find information not only on her parents, but also her grandparents.
Thomas Hill married Mary Wallace, d/o John Wallace and Jane Finley. John fought in the Revolutionary War. More about them later.
Your query dated 17 Mar 2012 asked what county in Kentucky Thomas and Mary Hill lived in. I believe it may be Fayette county, as that is where John Wallace was when he died. That is where I'm going to start my search for John.
Please contact me, if you care to. I have more information.