The 63d Division was activated 15 Jun 43 at Camp Blanding, Florida and trained under VII and II Corps. The division then moved to Camp Van Dorn, Mississippi on 22 Aug 43 and trained under IX and XXI Corps. The division staged at Camp Shanks ,New York from 28 Dec 44 until departing from New York City (Port of Embarkation) on 5 Jan 45. They arrived in France on 14 Jan 45 and entered Germany 20 Mar 45. The division returned to Boston (Port of Embarkation) on 26 Sep 45 and inactivated at Camp Myles Standish, Massachusetts on 27 Sep 45.
Advanced elements of the division arrived in Marseilles, France on 8 Dec 44, trained at Haguenau, and organized as Task Force Harris to protect the east flank of the drive on the Rhine. It defended the Vosges and Maginot Line area 22-30 Dec 44 and battled the German offensive south of Bitche 1-10 Jan 45. The rest of the division closed in Marseilles, France 14 Jan 45 and the division assembled at Willerwald on 2 Feb 45 as Task Force Harris was discontinued. The division conducted patrolling activity until 15 Feb 45 when the 255th Infantry attacked the Bois de Blies Brucken and the 253d Infantry fought the Battle for Auersmacher 17-19 Feb 45. The division completed the reduction of the Welferding salient with the capture of Buebingen and Bliesransbach 24 Feb 45.
The division renewed its attacks 3 Mar 45 as the 253d Infantry battled through heavily defended forest to Hahnsbusch 3-5 Mar 45. The division attacked the West Wall near Saarbruecken on 15 Mar 45 and took Fechigen, Eschringen, and Ensheim. After heavy combat, the division breached a gap in the West Wall north of the latter town on 18 Mar 45. With the fall of St. Ingbert and Hassel to the 255th Infantry on 20 Mar 45, the West Wall was pierced. After a brief rest, the division crossed the Rhine at Neuschloss on 28 Mar 45 and relieved the 44th Infantry Division, crossing the Neckar in the Wieblingen area on 30 Mar 45 and reaching Heidelberg. The division continued to advance behind the 10th Armored Division and fought through the region north of the Jagst River on 3 Apr 45. The 253d Infantry forced the river in the Griesheim-Herbolzheim region on 4 Apr 45 and fought house-to-house in Moeckmuehl. After frontal assaults against Hardenhauser Forest failed, the division enveloped the woods by 8 Apr 45. The 255th Infantry reached the Kocher River and established a bridgehead at Weissbach on 9 Apr 45.
The Kocher River bridgehead was expanded against strong German opposition and the 10th Armored Division attacked out of it on 11 Apr 45. The division mopped up in that area and consolidated on 14 Apr 45, returning to the attack the next day as it took Schwaebisch Hall with armored support by 18 Apr 45. The 254th Infantry crossed the river on a damaged bridge in Riedheim and repulsed a German armored counterattack. The division was relieved 28 Apr 45 and withdrawn from the line. It was assigned security duty from the Rhine to Darmstadt and Wurzburg on a line to Stuttgart and Speyer, and was in this mode when hostilities were declared ended on 7 May 45.