Gerhard Luke Luhn (1831-1920) was born in Elbergen, Hanover, Germany, and immigrated to the United States with his parents in 1845. He joined the Army's 6th Infantry in 1853 and saw service on the northern plains prior to the Civil War. In 1863 he became a second lieutanant in the 4th Infantry and was present at the Gettysburg Battle. He remained in the Army until his retirement in 1895. Among the forts he served at were Forts Laramie (1868), Bridger (1857, 1873, 1879), Fetterman (1874), Sanders (1877), and D.A. Russell (1878). He was with General William S. Harney's 1856 Sioux campaign and General George Crook's 1876 expedition and fought in the Battle of the Rosebud against Sitting Bull.
From the description of Papers, 1863-1918. (University of Wyoming, American Heritage Center). WorldCat record id: 27744636