Sherman's March on Atlanta was a 19th century Earth military campaign that occurred during the American Civil War. The March was led by its namesake, Major General Sherman of the Union Army.
Among the battles fought en route was the Battle of Pine Mountain, which included the 102nd New York Infantry, commanded by Colonel Thaddius "Old Iron Boots" Riker.
Thaddius Riker's descendant, William T. Riker recalled Sherman's March when describing the history behind the image of Thaddius Riker, and an unknown soldier who saved him during the battle. (VOY: "Death Wish")