The U.S. Army was founded on June 14, 1775, when the Continental Congress authorized enlistment of riflemen to serve the United Colonies for one year. For more on the history of the U.S. Army birthday, click here: the Army birthday
Infantry, June 14, 1775
Ten companies of riflemen were authorized by a resolution of the Continental Congress on June 14, 1775. However, the oldest Regular Army infantry regiment, the 3d, was constituted on June 3, 1784, as the First American Regiment.
Adjutant General's Corps, June 16, 1775
The post of Adjutant General was established June 16, 1775, and has been continuously in operation since that time. The Adjutant General's Department, by that name, was established by the act of March 3, 1813, and was redesignated the Adjutant General's Corps in 1950.
Corps of Engineers, June 16, 1775
Continental Congress authority for a "Chief Engineer for the Army" dates from June 16, 1775. A corps of Engineers for the United States was authorized by the Congress on March 11, 1779. The Corps of Engineers as it is known today came into being on March 16, 1802, when the President was authorized to "organize and establish a Corps of Engineers ... that the said Corps ... shall be stationed at West Point in the State of New York and shall constitute a Military Academy." A Corps of Topographical Engineers, authorized on July 4, 1838, was merged with the Corps of Engineers on March 1863.
Finance Corps, June 16, 1775
The Finance Corps is the successor to the old Pay Department, which was created in June 1775. The Finance Department was created by law on July 1, 1920. It became the Finance Corps in 1950.
Quartermaster Corps, June 16, 1775
The Quartermaster Corps, originally designated the Quartermaster Department, was established on June 16, 1775. While numerous additions, deletions, and changes of function have occurred, its basic supply and service support functions have continued in existence.
Air Defense Artillery and Field Artillery, November 17, 1775
The Continental Congress unanimously elected Henry Knox "Colonel of the Regiment of Artillery" on November 17, 1775. The regiment formally entered service on January 1, 1776.
Armor, December 12, 1776
The Armor branch traces its origin to the Cavalry. A regiment of cavalry was authorized to be raised by the Continental Congress Resolve of December 12, 1776. Although mounted units were raised at various times after the Revolution, the first in continuous service was the United States Regiment of Dragoons, organized in 1833. The Tank Service was formed on March 5, 1918. The Armored Force was formed on July 10, 1940. Armor became a permanent branch of the Army in 1950.
Ordnance Corps, May 14, 1812
The Ordnance Department was established by act of Congress on May 14, 1812. During the Revolutionary War, ordnance material was under supervision of the Board of War and Ordnance. Numerous shifts in duties and responsibilities have occurred in the Ordnance Corps since colonial times. It acquired its present designation in 1950.
Signal Corps, June 21, 1860
The Signal Corps was authorized as a separate branch of the Army by act of Congress on March 3, 1863. However, the Signal Corps dates its existence from June 21, 1860, when Congress authorized the appointment of one signal officer in the Army, and a War Department order carried the following assignment: "Signal Department--Assistant Surgeon Albert J. Myer to be Signal Officer, with the rank of Major, June 27, 1860, to fill an original vacancy."
Chemical Corps, June 28, 1918
The Chemical Warfare Service was established on June 28, 1918, combining activities that until then had been dispersed among five separate agencies of Government. It was made a permanent branch of the Regular Army by the National Defense Act of 1920. In 1945, it was redesignated the Chemical Corps.
Military Police Corps, September 26, 1941
A Provost Marshal General's Office and Corps of Military Police were established in 1941. Prior to that time, except during the Civil War and World War I, there was no regularly appointed Provost Marshal General or regularly constituted Military Police Corps, although a "Provost Marshal" can be found as early as January 1776, and a "Provost Corps" as early as 1778.
Transportation Corps, July 31, 1942
The historical background of the Transportation Corps starts with World War I. Prior to that time, transportation operations were chiefly the responsibility of the Quartermaster General. The Transportation Corps, essentially in its present form, was organized on July 31, 1942.
Military Intelligence, July 1, 1962
Intelligence has been an essential element of Army operations during war as well as during periods of peace. In the past, requirements were met by personnel from the Army Intelligence and Army Security Reserve branches, two-year obligated tour officers, one-tour levies on the various branches, and Regular Army officers in the specialization programs. To meet the Army's increased requirement for national and tactical intelligence, an Intelligence and Security Branch was established in the Army effective July 1, 1962, by General Orders No. 38, July 3, 1962. On July 1, 1967, the branch was redesignated as Military Intelligence.
Aviation, April 12, 1983
Following the establishment of the U.S. Air Force as a separate service in 1947, the Army began to develop further its own aviation assets (light planes and rotary wing aircraft) in support of ground operations. The Korean War gave this drive impetus, and the war in Vietnam saw its fruition, as Army aviation units performed a variety of missions, including reconnaissance, transport, and fire support. After the war in Vietnam, the role of armed helicopters as tank destroyers received new emphasis. In recognition of the growing importance of aviation in Army doctrine and operations, Aviation became a separate branch on April 12, 1983, and a full member of the Army's combined arms team.
Special Forces, April 9, 1987
The first Special Forces unit in the Army was formed on June 11, 1952, when the 10th Special Forces Group was activated at Fort Bragg, North Carolina. A major expansion of Special Forces occurred during the 1960s, with a total of eighteen groups organized in the Regular Army, Army Reserve, and Army National Guard. As a result of renewed emphasis on special operations in the 1980s, the Special Forces Branch was established as a basic branch of the Army effective April 9, 1987, by General Orders No. 35, June 19, 1987.
Army Medical Department, July 27, 1775
The Army Medical Department and the Medical Corps trace their origins to July 27, 1775, when the Continental Congress established the Army hospital headed by a "Director General and Chief Physician." Congress provided a medical organization of the Army only in time of war or emergency until 1818, which marked the inception of a permanent and continuous Medical Department. The Army Nurse Corps dates from 1901, the Dental Corps from 1911, the Veterinary Corps from 1916, the Medical Service Corps from 1917, and the Army Medical Specialist Corps from 1947. The Army Organization Act of 1950 renamed the Medical Department as the Army Medical Service. On June 4, 1968, the Army Medical Service was redesignated the Army Medical Department.
Chaplains, July 29, 1775
The legal origin of the Chaplains is found in a resolution of the Continental Congress, adopted July 29, 1775, which made provision for the pay of chaplains. The Office of the Chief of Chaplains was created by the National Defense Act of 1920.
Judge Advocate General's Corps, July 29, 1775
The Office of Judge Advocate of the Army may be deemed to have been created on July 29, 1775, and has generally paralleled the origin and development of the American system of military justice. The Judge Advocate General's Department, by that name, was established in 1884. Its present designation as a corps was enacted in 1948.
Civil Affairs, August 17, 1955
The Civil Affairs/Military Government Branch in the Army Reserve Branch was established on August 17, 1955. Subsequently redesignated the Civil Affairs Branch on October 2, 1959, it has continued its mission to provide guidance to commanders in a broad spectrum of activities ranging from host-guest relationships to the assumption of executive, legislative, and judicial processes in occupied or liberated areas.