| 1917–21, 1967–71|
| United States Army|
| United States of America|
The 11th Infantry Brigade (Light) is an inactive infantry brigade of the United States Army. It was first formed as part of the United States Army's 6th Division during World War I. It is best known for its service with the 23rd Infantry Division from 1967 through 1971 in the Vietnam War. The brigade is known for its responsibility in the My Lai Massacre.
11th Infantry Brigade (United States) Wikipedia
Activated: November 1917
Elements:51st Infantry Regiment
52nd Infantry Regiment
16th Machine-Gun Battalion
11th Field Artillery Battalion
Overseas: June 1918 Days of combat: 43 Returned to U.S.: June 1919 Inactivated: 30 September 1921 at Camp Grant, Illinois
Brigade Headquarters was inactive through World War II after the US Army reorganized its divisions from two brigades of two regiments (the Square Division), into one of three regiments with no brigades (the Triangular Division) concept.
The brigade was organized as a separate infantry brigade at Schofield Barracks, Hawaii as the first element of the 6th Infantry Division. The 6th Infantry Division was scheduled to be activated for deployment to Vietnam but Secretary of Defense McNamara cancelled its activation. The 11th Infantry Brigade was deployed, and during the Vietnam War served in the United States Army's 23rd Infantry Division (called the Americal Division). Elements of the brigade were responsible for the My Lai massacre where members of the brigade's 1st Battalion, 20th Infantry Regiment murdered between 340 and 500 civilians in 1968. Many of its former servicemen were interviewed in the documentary Four Hours in My Lai.
In June 1971, then Brigadier General John W Donaldson, former commander of the Brigade would be accused and later acquitted of killing 6 Vietnamese civilians on operations between November 1968 and January 1969.
Order of battle:Headquarters & Headquarters Company
3rd Battalion, 1st Infantry
4th Battalion, 3rd Infantry
1st Battalion, 20th Infantry
4th Battalion, 21st Infantry
6th Battalion, 11th Artillery
6th Support Battalion
6th Engineer Company
52nd Military Intelligence Detachment
Troop E, 1st Cavalry