The 11th Infantry Brigade (Light) was an infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

 brigade

Brigade

A brigade is a major tactical military formation that is typically composed of two to five battalions, plus supporting elements depending on the era and nationality of a given army and could be perceived as an enlarged/reinforced regiment...

 of the United States Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

. It was first formed as part of the United States Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

's 6th Division during World War I, however it is best known for its service as a separate Brigade in the Vietnam War

Vietnam War

The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...

. It was active from 1967 through 1971.

World War 1

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
Deactivated: 30 September 1921 at Camp Grant, Illinois

Brigade Headquarters was inactive through World War II after the US Army reorganized its Divisions from 2 brigades of 2 regiments (the Square Division

Square division

A square division is a designation given to the way military divisions are organized. In a square organization, the division's main body is composed of four regimental elements. Since a regiment could be split into separate battalions for tactical purposes, the natural division within a division...

), into one of 3 regiments with no brigades (the Triangular Division

Triangular division

A triangular division is a designation given to the way divisions are organized. In a triangular organization, the division's main body is composed of three regimental maneuver elements. These regiments may be controlled by a brigade headquarters or directly subordinated to the division commander...

) concept.

Vietnam

The brigade was organized as a separate Infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

 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

Robert McNamara

Robert Strange McNamara was an American business executive and the eighth Secretary of Defense, serving under Presidents John F. Kennedy and Lyndon B. Johnson from 1961 to 1968, during which time he played a large role in escalating the United States involvement in the Vietnam War...

 cancelled its activation. The 11th Infantry Brigade was deployed, and during the Vietnam War

Vietnam War

The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...

 served in the United States Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

's 23rd Infantry Division (called the Americal Division)

Americal Division

The 23rd Infantry Division, more commonly known as the Americal Division of the United States Army was formed in May 1942 on the island of New Caledonia. In the immediate emergency following Pearl Harbor, the United States had hurriedly sent three individual regiments to defend New Caledonia...

. It was responsible for the My Lai massacre where members of the brigade murdered over 500 civilians in 1968 under the command of Lieutenant Colonel Frank A. Barker.

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
  11th Field Artillery Regiment (United States)
  The 11th Field Artillery Regiment is an Field Artillery regiment of the United States Army first formed in 1916-History:The 11th Field Artillery was Constituted 1 July 1916 in the Regular Army at Camp Douglas-Lineage:...
  
  
• 6th Support Battalion
• 6th Engineer Company
• Troop E, 1st Cavalry