What a good question! Eck Robertson, Charlie Poole, Sam Long, Fiddlin' John Carson, Mac and Bob, Ernest Stoneman~~these are just a few of the great country musicians before Rodgers! There are a number of good sites (and books~~remember books?) that discuss this sort of thing. It is too late tonight to go gathering things up for you, but I will see what I can do later.

For starters though, many (not all) recognize the 1922 recording of Sally Goodin/Arkansas Traveler by Eck Robertson as the beginning of it all, at least as far as recordings are concerned.

Of course, you seem to be holding to the theory that country music evolved after Rodgers. In that case, it is a little more difficult to define. Again, a great number would credit Roy Acuff and/or Ernest Tubb for that honor, for a variety of reasons. Further discussion would take a lot more time than I have at the moment. I am sure that Gene and a few others will have a lot to say on this matter as well! (I just wanted to get the first installment of my two cents worth in)