Captain Miller was a holographic character in a World War II scenario stored in the holodeck of USS Voyager. Miller was a US Army captain serving in the 5th Armored Infantry, which, according to his uniform assignment patch, was a part of the 29th Infantry Division.
When the Hirogen took over Voyager in 2374 and forced the crew to participate in the 1940s-era program, Chakotay was forced into the role of Miller. (VOY: "The Killing Game", "The Killing Game, Part II")