The New Sentinel has a neat article (subscription required) profiling Knoxville businesses that are over 100 years old. I was surprised that Crouch Florist (1865) is the oldest, followed by Knoxville Iron (1868, now Gerdau Long Steel North America), and Mayo's (1878).

Another interesting tidbit is that Knoxville at one point (1894) Knoxville had two competing phone companies that could not interconnect calls between their exchanges until Southern Bell took them over. The first phone company started in 1882.