On the same day , German Army Group G ( Heeresgruppe G ) and Army Group Upper Rhine ( Heeresgruppe Oberrhein ) launched a major offensive against the thinly stretched , line of the Seventh U.S. Army .
On the same day , German Army Group G ( `` Heeresgruppe G '' ) and Army Group Upper Rhine ( `` Heeresgruppe Oberrhein '' ) launched a major offensive against the thinly stretched , 70 mi line of the Seventh U.S. Army .