Where do these concepts come from? 

The article was recently revised to say that Old Town is "in Williamson County, near Franklin" (no longer "in" Franklin) and that the mound complex "is alongside the Harpeth River on what later became one branch of the Natchez Trace" (no longer simply "on the Harpeth River branch of the Natchez Trace").

I'm puzzled by these changes, which aren't sourced. My investigations (call them "original research") using online maps do indicate that Old Town is in northwestern Williamson County, near Franklin, but not inside the current city limits or even in the urban growth boundary. Thus, I think the geographic location is OK, even though sources have placed it "in" Franklin. 

Let me get this straight.  You want to use insulting language about the edits, but then agree that they are factually correct.  Where is the OR?  I disagree that it is OR to state that the location is in Williamson County.  Whether or not it is currently in the current city limits is a factual matter that I am not actually sure about, but in the historic sweep it is correct to say that the location is near Franklin (think of Franklin having been a small town at one time).  It is "near" Franklin, meaning it is not in modern downtown Franklin.  I see no OR.  

However, I can't agree with "is alongside the Harpeth River on what later became one branch of the Natchez Trace". First off, what is later than "is"? It appears to me that the mound complex "is" alongside the Harpeth River and "is" on the Harpeth River branch of the Natchez Trace. I surmise that the intent was to say that the site was not on a branch of the Natchez Trace when the mound complex was built, but I don't buy that. First off, the previous version of the article never said that the mound complex was built on the Harpeth River branch of the Trace; it merely said that it's there now. Secondly, I'm not aware of any source indicating that the mound complex was not built on the Harpeth River branch of the Trace. Notwithstanding whatever the current version of the [[Natchez Trace[[ article, it's my understanding (based on diverse sources) that the Trace (which is an interconnected collection of trails, not a single trail) existed for centuries before white people laid eyes on Tennessee, and that archaeologists who have investigated Old Town assume that it was located where it is because of the river, the Trace, and the crossing of Brown's Creek. If the intent was to say that the Trace did not exist when the mound complex was built, I see that as a piece of WP:OR that's inconsistent with many sources.   

Those amendments to the article were in 2 edits, the main one with edit summary "revise about assertion of location, avoiding unnecessary disclosure and avoiding synthesis (e.g. about 2 creeks being the same, not in a source AFAIK). Drop dup cat.".  Funny you should be making accusations of original research.  I think the wp:OR accusation should apply more strongly to the previous language, which included wp:OR in the form of synthesis (wp:SYNTH?) about which creek is what (and the synthesis ends up disclosing more about location than is necessary).  I think that "the Harpeth River branch of the Natchez Trace" refers pretty clearly to that branch of the 1800's Natchez Trace, which served as path/roadway for return upstream of persons who had brought rafts or barges down the Mississippi to New Orleans.  The other branch is known as the Ridge Route or something like that and is covered in a different NRHP listing.  These two distinct branches are known in history and described in historical documents, including being described in Williamson County MRA and other documents that Orlady has read.  To refer to the prehistoric mounds having been built along the 1800s-era historic "Harpeth River branch of the Natchez Trace" is wp:OR, wp:SYNTH, ahistorical, sloppy, generally bad, in poor taste, and whatever else sounds negative, more so than the language which replaced the original language.

OR is bad.  OR was removed by the edits.  OR was not introduced by the edits.  Yay!  Glad we are all agreed.  I am sure there are improvements to the language which can be made, but I would prefer not to argue small wording changes until the bigger article structure questions being discussed above are settled.  Or until Orlady agrees to allowing a third party to judge on wording, and replies about participating in mediation to address the long pattern of conflict. ncram