Photo at Chess.com. Caption: This photograph shows an earnest game of chess between Colonel (afterward Major-General) Martin T. McMahon, assistant adjutant-general of the Sixth Corps, Army of the Potomac, and a brother officer, in the spring of 1864 just preceding the Wilderness campaign. Colonel McMahon, who sits near the tent-pole, is evidently studying his move with care. The young officer clasping the tent-pole is one of the colonel’s military aides. Chess was also fashionable in the Confederate army, and it is recorded that General Lee frequently played chess with his aide, Colonel Charles Marshall, on a three-pronged pine stick surmounted by a pine slab upon which the squares had been roughly cut and theblack ones inked in. Napoleon Bonaparte is said to have been another earnest student of chess.
Posted by Ed Darrell 
Millard Fillmore's Bathtub 