Having the 1st Brazilian Infantry and the 6th South African Armoured Divisions in its ranks, in addition to the United States 1st Armored, the 92nd Infantry and the 10th Mountain Divisions, Crittenberger's IV Corps were in combat for over 390 days, 326 of them engaged in continuous combat. Crittenberger commanded IV Corps, still part of the Fifth Army, now commanded by Lieutenant General Lucian Truscott (like Crittenberger, a cavalryman whom Crittenberger had taught while he was an instructor at the United States Army Cavalry School), after Lieutenant General Clark was promoted to the command of 15th Army Group, as the western arm of the Allied thrust through northern Italy (codenamed Operation Grapeshot) to the Po River, capturing large numbers of German troops, which ended with the surrender of the remaining German forces in Italy on May 2, 1945. The end of World War II in Europe came soon after, followed by the surrender of Japan on September 2, 1945, almost exactly six years since the war had begun. During the campaign in Italy Crittenberger operated alongside Major General Geoffrey Keyes, another of Crittenberger's West Point classmates, who was commanding II Corps.