Peachtree was a northern province of Detina. It seceded with "King" Geoffrey. It became a major battleground during the Detinan Civil War. It was lost due to various mistakes committed by the ever-changing (there is a lot of intrigue and conflict among the northern officers) northern commanders: General Thraxton the Braggart, Joseph the Gamecock, and the infamous Bell to the southron host, which were commanded by first General Guildenstern, Marshal Bart, and General Hesmucet.
Peachtree is analogous to the State of Georgia, which is closely associated with its peach groves, and is known as "the Peach State" (among other things).