History: Constituted on 13 October 1950 in the Regular Army as HHC, 501st Communication Reconnaissance Group, the unit was activated on 20 October 1950 at Camp Pickett, Virginia, and assigned to the Army Security Agency. On 29 May 1951, the 501st Transferred from Camp Pickett to Camp Stoneman, California for staging to Pusan, Korea.

The 501st arrived at Pusan on 25 June 1951. The unit spent four days in the Pusan assembly area awaiting sea transportation to Inchon. The 501st arrived at Inchon on 1 July 1951. The Group Headquarters moved into the war damaged main building of the Kyonggi Middle School, Seoul, Korea. By 15 July, the 501st had assumed administrative and operational control of all ASA units in Korea.

The 501st Communications Reconnaissance Group represented a first of its kind and a milestone in intelligence support to U.S. tactical forces. The Korean War presented ASA with an opportunity to test its newly formed doctrine in support of a field Army. ASA activated the 501st to direct operations of ASA support units in the Korean Theater, coordinating all ASA activities at each of the lower echelons.

By the end of hostilities in July 1953, the Group had three battalions and five companies assigned. Besides the numerous citations awarded to its subordinate units, the Group received the Meritorious Unit Commendation (1 July 1951 to 27 July 1953), the Republic of Korea Presidential Unit Citation (15 July 1951 to 30 April 1953) and credit for participation in six campaigns.

On 28 January 1956, the 501st Communications Reconnaissance group was redesignated at HHC, 501st Army Security Group. On 1 July 1956, the 501st ASA group was inactivated and its personnel and mission transferred to the 508th USASA Group, a TDA organization, as part of a worldwide reorganization occurring within the Army Security Agency to provide greater flexibility in support to tactical units.

On 1 January 1978, HHC, 501st ASA group was redesignated HHC, 501st Military Intelligence Group and activated at Yongsan, Korea. The Group took the place of the temporary 501st MI Group (Provisional), organized at Camp Coiner on 1 April 1977, as part of the major reorganization within Army Intelligence which merged individual disciplines into one organization.

On 15 April 1986, the 501st was elevated to brigade status under the Army of Excellence guidelines.