1st infantry division (us army)
The 1st Infantry Division is a combined arms division of the United States Army, founded on 24 May 1917. It is the oldest continuously serving division in the Regular Army. It has seen continuous service since its organization in 1917 during World War I. It was officially nicknamed "The Big Red One" after its shoulder patch (see post #5662159). It is currently based at Fort Riley, Kansas.
Wikipedia page: 1st Infantry Division (United States)