Billy, I did a google search and this is what I found. "Yard sales and the Meriweather Lewis Arts and Crafts Fair are on the second full weekend in October and coincide with Ocktoberfest in Hohenwald, TN." It also said that the yard sales extended for miles in every direction from Hohenwald.
Since you said in your PDA that you were going to Hohenwald, I'm sure this is the one you were at. The Longest Yard Sale on Rt. 127 is always in August, according to their web site. I actually found that there are several highway yard sales in Kentucky and Tennessee during the summer.