The First Infantry Division, often referred to as "The Big Red One" after its shoulder patch, was originally formed in 1917 as part of the American Expeditionary Force and is the oldest division in the United States Army. The division has fought in both World War I and World War II, the Vietnam War, and both the first and second Gulf Wars.
Among the many firsts recorded by the division are being the first division to arrive in France during World War I and the furthest to advance into Germany by that war's end. The Big Red One was also one of the first American units to arrive in England during the Second World War and was among the units landing in North Africa and Sicily. The division was first ashore at D-Day, coming ashore at Omaha Beach and driving east in continuous action for six months, capped with the capture of the first German city by American troops, Aachen. The 1st would go on to fight in the bloody battle of the Hurtgen Forest and the subsequent Battle of the Bulge, thereafter continuing its advance through Germany and into Czechoslovakia.
The division did not take part in the Korean War, remaining in Germany on occupation duty and later, as a deterrent to potential Soviet adventurism.
The Big Red One was first on the ground in Vietnam as well, arriving in 1965 and involved in heavy combat in War Zone C northwest of Saigon until recalled to Fort Riley in 1970, after which the bulk of the division remained in Kansas with one brigade "forward deployed" to Germany.
While the "Big Red One" was one of the units taking part in the 2003 invasion of Iraq, it withdrew in 2005 and since then has not deployed as a complete unit, with only individual brigades being sent back to Iraq and into Afghanistan.