(covers information that was retroactively changed)
General Robert Edward Lee was a 19th century Human who served as the commanding officer of the Confederate Armies during the American Civil War. Although he held the rank of a senior general, Lee preferred to wear a colonel insignia, three gold stars, on each collar of his uniform.
A painting entitled The Last Meeting of Lee and Jackson at Chancellorsville, which depicted Lee (left) and Stonewall Jackson, another famous Confederate general, during their final meeting on May 2, 1863, was stored in the USS Enterprise's library computer in 2254, and was among the materials viewed by the Talosians when they scanned the Enterprise computer. (TOS: "The Cage")
Although not mentioned by name in dialogue, the painting of General Lee, wearing Confederate colonel's stars, appeared on a viewscreen of the library computer in the original 1964/65 version of the episode.