| IV Corps | |
|---|---|
 | |
| Active | 1918–19 1922–45 1958–68 |
| Country |  United States |
| Branch |  Army |
| Size | Corps |
| Engagements | World War I
|
| Commanders | |
| Notable commanders | Charles Henry Muir Douglas MacArthur Stanley Dunbar Embick Alexander Patch Willis D. Crittenberger |
| U.S. Corps (1939–present) | ||||
|
IV Corps was acorps-sized formation of theUnited States Army that saw service in bothWorld War I andWorld War II.
The corps was first organized on 20 June 1918, duringWorld War I as part of theAmerican Expeditionary Forces. Under Major GeneralCharles H. Muir serving on theWestern Front, asHeadquarters IV Army Corps. It participated in the offensivesof St. Mihiel and Lorraine, being demobilized inGermany on 11 May 1919.[1]
The IV Corps was reconstituted in theOrganized Reserve in 1921, allotted to the FourthCorps Area, assigned to theSecond United States Army, and activated with a headquarters composed of Regular Army and Organized Reserve personnel atAtlanta, Georgia, on 1 March 1922. The Headquarters Company was initiated on 29 March 1922 in Atlanta. on 15 June 1925, the headquarters was relieved from active duty, with all Regular Army personnel passing to the control of the Headquarters, Non-Divisional Group, Fourth Corps Area, which assumed the responsibilities of the IV Corps headquarters; both the Headquarters and Headquarters Company remained active in the Organized Reserve. The Headquarters, IV Corps, was withdrawn from the Organized Reserve on 15 August 1927 and allotted to the Regular Army, as was the Headquarters Company on 1 October 1933. The corps headquarters was partially activated at Atlanta with Regular Army personnel from the corps area headquarters and Reserve personnel from the corps area at large. On 1 October 1933, the IV Corps was relieved from the Second Army and assigned to the Third Army. For major maneuvers and command post exercises in the 1930s, the corps headquarters was occasionally organized provisionally using its assigned Reserve officers and staff officers from the Fourth Corps Area. The corps headquarters was fully activated on 20 October 1939, less Reserve personnel, atFort Benning, Georgia.[2]
Continuing the lineage of the World War I IV Corps, a second IV Corps was constituted in the Regular Army and activated on 27 June 1944 in Italy, being consolidated with the second, active, IV Corps that had been formed in 1922.[3] IV Corps replaced theVI Corps in theU.S. Fifth Army'sorder of battle in theItalian campaign, afterAllied forces liberatedRome in the summer of 1944 and VI Corps was subsequently withdrawn from Italy to take part inOperation Dragoon, the Allied invasion of southern France. Initially the corps had two divisions—theU.S. 1st andSouth African 6th Armoured Divisions—but was reinforced with theU.S. 92nd Infantry Division from August, the1st Brazilian Infantry Division from September, and theU.S. 10th Mountain Division in February 1945, as well as theU.S. 85th Infantry Division in April.[4]
Under command ofMajor GeneralWillis D. Crittenberger, the IV Corps took part in the fighting through the summer of 1944 as the Fifth Army, under the command ofLieutenant GeneralMark W. Clark, and theBritish Eighth Army, commanded byLieutenant GeneralSir Oliver W. H. Leese, advanced north to theRiver Arno. In the autumn and winter of 1944, the IV Corps formed the central wing of the Fifth Army's sector, taking the major role in the Fifth Army's assault on theGothic Line in the centralApennine Mountains, fighting to break through to the Lombardy plains beyond.[4][5][6]
In the spring of 1945 the corps, still in the Fifth Army's central sector, took part in the successfulItalian spring offensive, breaking out of the Apennines to outflank the units of theGerman Tenth andFourteenth Armies defendingBologna and forming a pincer with the British Eighth Army on the right to surround them, and then driving on to theRiver Po and finallyVerona andBrescia.
The corps was inactivated on 13 October 1945, at Camp Kilmer, New Jersey, it was reactivated again at Birmingham, Alabama, in 1958 and inactivated at Birmingham in 1968.[7]