This map of Fort Sanders (Knoxville, TN) was drawn by John G Orth of Arcadia Ohio. According to his handwritten note on the back of the map, Orth enlisted in Co G 118th Ohio Infantry 8/22/1862 and mustered out with his company on 6/24/1865. In late 1863, Orth and the 118th Ohio were part of Burnside's campaign in East TN. On the back of the well executed, hand-drawn map, Orth provides a legend for features he has included and details the hanging of "E S Dodd" of the 8th Texas Cavalry.
Since it's a bit difficult to read, Ill provide a transcription: "....20 Is what is knowan[sic] to be Gallows Hill. Since the commencement of the Rebellion, the plase[sic] whair[sic] union men ware[sic] hung for being Lawyal[sic] to the Government. And we have used the Same Ground & Gallows on the 8th of January  to hang a Rebel Spy by the name of E. S. Dodd of Comp'y D 8th Texas Cavelry[sic], Rebel army. W. Seifried of Comp. G 118th [Ohio] Regt Witnees'd The Sene[sic] &c."
- Ephraim Shelby Dodd's memorial at Find A Grave https://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=5783001
- A previous thread on Ephraim Shelby Dodd by @east tennessee roots which includes bio information.
- Ephraim Shelby Dodd's diary upon which evidence he was determined to be a spy and hung https://texashistory.unt.edu/ark:/67531/metapth14391/