Constituted 3 May 1861 in the Regular Army as Company A, 2d Battalion, 12th Infantry

Organized 20 May 1862 at Fort Hamilton, New York

Reorganized and redesignated 7 December 1866 as Company A, 21st Infantry

Consolidated 20 August 1869 with Company A, 32d Infantry (see ANNEX), and consolidated unit designated as Company A, 21st Infantry

(21st Infantry assigned 29 July 1918 to the 16th Division; relieved 8 March 1919 from assignment to the 16th Division; assigned 22 October 1921 to the Hawaiian Division (later redesignated as the 24th Infantry Division)

Redesignated 5 June 1958 as Headquarters and Headquarters Company, 1st Battle Group, 21st Infantry, and remained assigned to the 24th Infantry Division (organic elements concurrently constituted and activated 1 July 1958 in Germany)

Reorganized and redesignated 1 February 1963 as the 1st Battalion, 21st Infantry

Inactivated 15 April 1970 in Germany

Relieved 5 June 1972 from assignment to the 24th Infantry Division, assigned to the 25th Infantry Division, and activated at Schofield Barracks, Hawaii

ANNEX

Constituted 3 May 1861 in the Regular Army as Company A, 3d Battalion, 14th Infantry

Organized in August 1865 at Fort Trumbull, Connecticut

Reorganized and redesignated 21 September 1866 as Company A, 32d Infantry

Consolidated 20 August 1869 with Company A, 21st Infantry, and consolidated unit designated as Company A, 21st Infantry

1st Battalion
21st Infantry Honors

Campaign Participation Credit

Civil War Peninsula: * Manassas; * Antietam; * Fredericksburg; * Chancellorsville; * Gettysburg; * Wilderness; * Spotsylvania; * Cold Harbor; * Petersburg; Virginia 1862; * Virginia 1863

Indian Wars: Modocs; Nez Perces; Bannocks; Arizona 1866; Arizona 1867; * Arizona 1868; Arizona 1869; * Arizona 1870

War with Spain: * Santiago

Philippine Insurrection: * Zapote River; * Luzon 1899; * Luzon 1900; * Luzon 1901; Luzon 1902

World War I: * Central Pacific; * New Guinea (with arrowhead); * Leyte; * Luzon; * Southern Philippines (with arrowhead)

Korean War: * UN Defensive; * UN Offensive; * CCF Intervention; * First UN Counteroffensive; * CCF Spring Offensive; * UN Summer-Fall Offensive; * Second Korean Winter; * Korea, Summer 1953

Decorations

* Presidential Unit Citation (Army) for DEFENSE OF KOREA

Presidential Unit Citation (Army) for SANGHONGJONG-NI

* Philippine Presidential Unit Citation for 17 OCTOBER 1944 TO 4 JULY 1945

* Republic of Korea Presidential Unit Citation for PYONGTAEK

* Republic of Korea Presidential Unit Citation for KOREA