Editing Corps area (section)

==Corps area and army area organizations, 1921-1932==

An army area included three corps areas, and in the early years was concurrently staffed and headquartered with one of the corps areas. For example, First Army Area headquarters staff was also the Second Corps Area headquarters staff based at [[Fort Jay]] at [[Governors Island]] in New York, New York; Sixth Corps Area provided the Second Army Area headquarters staff.

===First Army Area===
First Army Area included First Army (Active) and Fourth Army (reserve on paper).

*'''[[First Corps Area]]''' replaced the Northeastern Department, and was headquartered in [[Boston Army Base]], Massachusetts, encompassing Maine, Massachusetts, New Hampshire, Rhode Island, Vermont and Connecticut. It was responsible for the mobilization, and administration of the [[First United States Army]] (1936–38); the Fourth Army, I Army Corps with 9th Division, 26th Division, 43d Division; XI Corps with three divisions; coast defense units of the First Coast Artillery District, some units of the GHQ Reserve, and the [[Zone of the Interior]] support units of the First Corps Area Service Command. First Corps Area was redesignated First CASC in May 1941.{{sfn|Clay|2010a|p=19}}
*'''Second Corps Area''' replaced the [[Eastern Department (United States Army)|Eastern Department]], headquartered at [[Fort Jay]] on [[Governors Island]] in New York City and encompassed New York, New Jersey, Delaware and from 1921 to 1937, the District of Puerto Rico. 
*Formations included the [[United States First Army]] (1921–36 and 1938–41); Fourth Army (1921–33); the [[II Corps (United States)]], with the [[1st Infantry Division (United States)|1st Infantry Division]], the only active division in the area; the [[27th Infantry Division (United States)|27th Infantry Division]] of the New York National Guard; and the [[44th Infantry Division (United States)|44th Infantry Division]] of the New Jersey, New York, and Delaware National Guards; and [[XII Corps (United States)]], assigned the [[77th Infantry Division (United States)|77th Division]], 78th Division, and 98th Division of the [[Organized Reserves]].{{sfn|Clay|2010a|p=26}} Also in the corps area was the [[21st Cavalry Division (United States)]] of the New York, Pennsylvania, Rhode Island, and New Jersey National Guards; the [[61st Cavalry Division (United States)|61st Cavalry Division]] of the Organized Reserves; the Second Coast Artillery District; and the Second Corps Area Service Command. 
*'''Third Corps Area''' variously headquartered at [[Fort McHenry]] and [[Fort Howard (Maryland)|Fort Howard]] in Baltimore, Maryland and included Pennsylvania, Maryland, District of Columbia and Virginia. Responsible for units of the First and Fourth Armies, III Army Corps ([[8th Infantry Division (United States)|8th]], 28, 29 Divisions) and [[XIII Corps (United States)|XIII Army Corps]] ([[79th Infantry Division (United States)|79th]], [[80th Division (United States)|80th]], [[99th Infantry Division (United States)|99th Division]]s, coast defense units of the Third Coast Artillery District, select units of the GHQ Reserve, and the Z.I. support units of the Third CASC.{{sfn|Clay|2010a|p=33}} From 15 October 1921, included the [[62nd Cavalry Division (United States)|62nd Cavalry Division]], Organized Reserves (also part of Fourth Army); included the [[2nd Combat Bombardment Wing|2d Observation Wing]], later 2d Wing, from 20 August 1920. From 1921 to 30 September 1927, [[Washington D.C.]] was withdrawn from the Third Corps Area and established as the District of Washington. After discontinuation, DC duties were taken on by the [[16th Infantry Brigade (United States)|16th Infantry Brigade]]. The [[14th Aero Squadron]] (or 14th Bombardment Squadron) was assigned to the Third Corps Area, August 28, 1933 and then transferred to the [[9th Bombardment Group]], on March 1, 1935. From 1940 to 1942, Third Corps Area was commanded by [[Walter S. Grant]],<ref>{{cite magazine |last=Birnie |first=Upton Jr. |date=October 1956 |title=Obituary, Walter S. Grant |url=https://digital-library.usma.edu/digital/collection/assembly/id/7659/rec/1 |magazine=Assembly |location=West Point, NY |publisher=Association of Graduates, United States Military Academy |pages=63–64 |via=West Point Digital Library |ref={{sfnRef|Birnie}}}}</ref> and the organization was designated the Third Corps Area Service Command in May 1941.

===Second Army Area===
Second Army Area included Second Army (Active) and Fifth Army (reserve on paper).

*'''[[Fourth Corps Area]]''' replaced the [[Southeastern Department]] based in Charleston, South Carolina and was originally headquartered there then transferred to Atlanta, Georgia, and encompassed the states of Alabama (for a period), Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee. Formations included Third Army (1936–40); IV Corps: [[4th Infantry Division (United States)|4th Division]], 30th Division, 31st Division; XIV Corps: 81st Division, 82d Division, 87th Division; Fourth Coast Artillery District; and [[Fourth Corps Area Service Command]].{{sfn|Clay|2010a|p=40}}
*'''[[Fifth Corps Area]]''' was established on 20 August 1920 with headquarters at [[Fort Benjamin Harrison]], Indiana, and organized from parts of the discontinued [[Central Department (United States Army)|Central Department]]. The headquarters was transferred to [[Fort Hayes]], [[Columbus, Ohio]], on 20 June 1922. The Fifth Corps Area included the states of Indiana, Ohio, West Virginia, and Kentucky. The headquarters was responsible for the units of the [[Second United States Army|Second]] and Fifth Armies, the V Army Corps (5th, 37th, and 38th Divisions) and XV Army Corps (83rd, 84th, [[100th Infantry Division (United States)|100th Infantry Division]]s), select GHQ Reserve units, and Zone of the Interior support units of the [[Fifth Corps Area Support Command]]. Mobile units of the corps area, less GHQ Reserve and Z.I. units, were assigned to the Second and Fifth Armies from 1921 to 1933. With the adoption of the four field army plan on 1 October 1933, the units of the Fifth Corps Area were reassigned to the Second Army, GHQR, or demobilized.{{sfn|Clay|2010a|p=48}}
*'''[[Sixth Corps Area]]''' covered the states of Wisconsin, Michigan and Illinois and [[Jefferson Barracks]], Missouri. The headquarters was established at [[Sheridan Reserve Center|Fort Sheridan]], Illinois, in August 1920, from portions of the former Central Department, but then moved to the [[U.S. Post Office]] Building at 1819 West Pershing Road in Chicago on 10 October 1921. Sixth Corps Area was responsible for the mobilization, administration, and training of units of the Second and Fifth Armies, I Cavalry Corps (Regular Army, but inactive, 1927–1940), VI Army Corps (including the Regular Army [[6th Infantry Division (United States)|6th Division]], [[32nd Infantry Division (United States)|32d]] and 33rd Divisions) and XVI Army Corps (85th, 86th, 101st Divisions), select GHQ Reserve units, and the Zone of the Interior support units of the [[Sixth Corps Area Support Command]].{{sfn|Clay|2010a|p=53}}

===Third Army Area===
Third Army Area included Third Army (Active), including, seemingly, the Reserve [[23rd Cavalry Division (United States)]], and Sixth Army (reserve on paper).

*'''[[Seventh Corps Area]]''' initially included Kansas, Minnesota, Missouri (but not Jefferson Barracks), North Dakota, South Dakota, Iowa and Nebraska. Responsibility for Arkansas was transferred from the Fourth Corps Area to the Seventh Corps Area on 1 December 1920. The headquarters was established on 20 August 1920 with headquarters at [[Fort Crook, Nebraska]], again from elements of the previous Central Department. HQ, Seventh Corps Area moved to Fort Omaha, NE, on 27 May 1922 and further moved to the Army Building at 15th and Dodge Streets in Omaha - the Omaha Army Depot - on 25 March 1929.{{sfn|Clay|2010a|p=59}} 
*'''[[Eighth Corps Area]]''', variously headquartered in Dallas and [[Fort Sam Houston]] in [[San Antonio]], Texas, replaced the Southern Department and included Texas, Oklahoma, Colorado, New Mexico and Arizona. From 1922-27 the [[44th Observation Squadron]] was attached to the Field Artillery School, initially at Post Field, Oklahoma. The [[154th Observation Squadron]] was assigned to the Eighth Corps Area on 16 September 1940, but was later reassigned to Third Army.
*At the end of General [[Frank M. Andrews]]' four-year term as Commanding General of [[GHQ Air Force]] on March 1, 1939, he was not reappointed, reverted to his permanent rank of colonel, and was reassigned as air officer for the Eighth Corps Area in San Antonio, the same exile to which [[Billy Mitchell]] had been sent. Possibly expected to retire, he instead was recalled to Washington just four months later by Marshall after President [[Franklin D. Roosevelt]] named [[George C. Marshall]] to serve as [[Chief of Staff of the United States Army]] following [[Malin Craig]]'s retirement.
*'''Ninth Corps Area''', headquartered at the [[Presidio of San Francisco]], California, replaced the [[Western Department]] and included Alaska, Idaho, Montana, California, Wyoming, Washington, Utah, Nevada and Oregon.<ref name=Matchette>{{Citation
  |last = Matchette
  |first = Robert
  |title =Guide to Federal Records in the National Archives of the United States
  |publisher=National Archives and Records Administration
  |year=1995
  |location = Washington, D.C.
  |display-authors=etal}}</ref> Included the [[41st Infantry Division (United States)|41st Division]], the [[18th Squadron (Observation)]] from October 1921 to July 1922; the [[19th Pursuit Squadron|19th Squadron (Pursuit)]] October 1921-June 1922; and the [[7th Bombardment Group]] from 1 June 1928 - c. 30 October 1931, and then again from c. 1 October 1933 - 1 March 1935. [[17th Attack Group]] was located at [[March Field]] from 1931 but reported to the [[1st Bombardment Wing]].{{sfn|Maurer|1983|p=373}} The 91st Aero Squadron, later the [[91st Observation Squadron]], was almost continuously associated with the Ninth Corps Area from its reformation on 20 August 1920 until 1940. The 805th Observation Squadron was constituted in the Organized Reserve (Oregon) on 31 March 1924; and was then consolidated on 8 December 1936, with the 805th Aero Squadron. Its mission was to provide aerial observation support to the Commanding General, Ninth Corps Area. The 805th Observation Squadron was inactivated on 11 June 1937 and then disbanded on 31 May 1942.{{sfn|Clay|2010c}} 

The [[Civilian Conservation Corps]] was organized roughly along army corps area boundaries since most of the logistical administration and support (food, housing, uniforms, transportation) for this 1930s Great Depression-era emergency work program was provided by the U.S. Army. The corps areas provided [[Regular Army (United States)|Regular Army]] officers to oversee these tasks. In time, they were replaced by officers of the Organized Reserve, freeing Regular Army officers to return to their assigned duties and providing practical experience to the Reserve officers.<ref name=CCC>{{Citation|title= Civilian Conservation Corps Legacy|url =https://ccclegacy.org/ccc-camp-lists/}}</ref>