I think your best bet is to go back step by step using BMD certificates.Birth certificates, to get parents names,and places they were born. This method worked beautifully for me, though my search was in England.We started with only one name, and just an aproximate place of birth, and now we have a very large amount of information on our Brindley roots.
Also, marriage certificates will give you more information regarding where they were living and their parents names, Census information can be very useful for filling in as you have found. If you know their religious leanings from which church they were married in, for instance, you might find baptismal information too. If any of your relatives were in the military you can sometimes get information from those sources.
You might try Cyndi's List of thousands of websites. Here is one for Kentucky one http://www.cyndislist.com/ky.htmhttp://www.cyndislist.com/ky.htm There may be some help here.