Bruce, I don't have any special knowledge regarding what the Feds were doing there, but had always just figured that in 1862 it was a forward outpost--just as Greenville was. Being out there in No Man's Land and exposed, my thinking is that Barnesville and Greenville were just a bit of a "Bridge To Far." The Feds abandoned Barnesville and set up shop in Centreville, and abandoned Greenville and set up shop in Patterson. Even so, Patterson and Centreville were still far too exposed, as is evidenced by the disasters inflicted upon the Union troops in those places on April 20, 1863 (Patterson) and December 23, 1863 (Centreville).