4th Battalion, 6th Infantry Regiment

The 4th Battalion, 6th Infantry Regiment was first constituted on 11 January 1812 in the Regular Army as a company of the 11th Infantry. It was organized between March and May 1812 in Vermont, New Hampshire, or Connecticut. It was consolidated between May and October 1815 with a company of the 25th Infantry (first constituted on 26 June 1812) and a company each of the 27th, 29th, and 37th Infantry (all constituted on 29 January 1813) to form a company of the 6th Infantry. It was designated on 22 May 1816 as Company D, 6th Infantry.

The unit was consolidated on 1 May 1869 with Company D, 42nd Infantry, Veteran Reserve Corps (first constituted 21 September 1866), and the consolidated unit was designated as Company D, 6th Infantry. The 6th Infantry as a whole was assigned on 18 November 1917 to the 5th Division and relieved in August 1921 from assignment to the 5th Division. It was assigned on 24 March 1923 to the 6th Division and relieved on 16 October 1939 from assignment to the 6th Division.

The unit was reorganized on 15 July 1940 as Company D, 6th Infantry (Armored), an element of the 1st Armored Division. It was redesignated on 1 January 1942 as Company D, 6th Armored Infantry, an element of the 1st Armored Division. The unit was again reorganized and redesignated 20 July 1944 as Company A, 11th Armored Infantry Battalion, an element of the 1st Armored Division. It was converted and redesignated on 1 May 1946 as Troop A, 11th Constabulary Squadron, an element of the 1st Constabulary Regiment before being inactivated on 20 September 1947 in Germany.

The unit was converted and redesignated on 7 April 1949 as Company A, 11th Armored Infantry Battalion, with the 11th Constabulary Squadron concurrently relieved from assignment to the 1st Constabulary Regiment. It was redesignated on 10 October 1950 as Company D, 6th Infantry and activated on 16 October 1950 in Germany. It was again inactivated on 1 June 1958 in Germany.

The unit was redesignated on 11 May 1959 as Headquarters and Headquarters Company, 4th Battle Group, 6th Infantry, withdrawn from the Regular Army, allotted to the Army Reserve, and assigned to the 102nd Infantry Division, with its organic elements concurrently constituted. The Battle Group was activated on 1 June 1959 with Headquarters at St. Louis, Missouri.

At that time its Headquarters and Headquarters Company was consolidated with Headquarters and Headquarters Company, 407th Infantry. Headquarters and Headquarters Company, 407th Infantry had been first constituted on 23 July 1918 in the National Army as Headquarters and Headquarters Company, 407th Infantry, an element of the 102nd Division. It was demobilized on 30 November 1918 before being reconstituted on 24 June 1921 in the Organized Reserves as an element of the 102nd Division, which was later redesignated as the 102nd Infantry Division. It was organized in November 1921 at St. Louis, Missouri and only ordered into active military service on 15 September 1942. At that time it was also reorganized at Camp Maxey, Texas. It was inactivated on 16 March 1946 at Camp Kilmer, New Jersey, but activated again 7 April 1947 at Danville, Illinois. Its location was changed on 15 March 1948 to St. Louis, Missouri. The Organized Reserves as a whole were redesignated on 25 March 1948 as the Organized Reserve Corps, before being redesignated on 9 July 1952 as the Army Reserve. When Headquarters and Headquarters Company, 407th Infantry and Headquarters and Headquarters Company, 4th Battle Group, 6th Infantry were consolidated, the resulting unit was designated as Headquarters and Headquarters Company, 4th Battle Group, 6th Infantry.

The unit was reorganized and redesignated on 1 April 1963 as the 4th Battalion, 6th Infantry and inactivated on 31 December 1965 at St. Louis, Missouri. It was withdrawn on 13 September 1972 from the Army Reserve, allotted to the Regular Army, relieved from assignment to the 102nd Infantry Division, and assigned to the United States Army Berlin Brigade. It was concurrently activated in Germany. The unit was inactivated on 29 June 1984 in Germany, and relieved from assignment to the Berlin Brigade.

The unit was assigned on 1 August 1984 to the 5th Infantry Division and activated at Fort Polk, Louisiana. It was inactivated on 16 December 1992 at Fort Polk, Louisiana, and relieved from assignment to the 5th Infantry Division.

The unit was redesignated on 1 October 2005 as the 4th Battalion, 6th Infantry Regiment. It was assigned on 16 March 2008 to the 4th Brigade Combat Team, 1st Armored Division, and activated at Fort Bliss, Texas.