During World War II, Sgt. Rock fought in the infantry branch of the U.S. Army in the European Theatre and eventually rose to authority within his unit, Easy Company. The unit was a collection of disparate individuals who managed to participate in every major action in the European war. Generally he is considered to have come from Pittsburgh, Pennsylvania, where he worked in a steel mill. Enlisting after the attack on Pearl Harbor, he went to North Africa as a private but promotion came quickly as his superiors were killed, to assistant squad leader, squad leader, and then platoon sergeant. Rock has two siblings, Larry a Marine serving in the Pacific and Amy a nun. Rock also usually wears the chevrons and rockers of a Master Sergeant on his uniform and also applied, oversize, to the front of his helmet.

• Rock is a crack shot, able to shoot down several German fighter planes with a single submachine gun, and able to throw hand grenades with amazing accuracy.
• Rock is a highly effective close combat fighter, mostly shown using a style of streetfighting mixed with boxing.
• Rock seems to have close to superhuman endurance and strength, surviving large number of gunshot wounds, fragments from hand grenades, exposure to freezing water and other hazards.
• Rock’s “Combat Antenna” is what he calls a kind of sixth sense to warn him of impending enemy attack. This usually allows him at least some time to warn Easy Co. even if it rarely allows them to get out of harm’s way entirely.
• Rock also has a heart. The one thing that (almost) had him breaking down is when the Nazis scraped the very bottom of the barrel and were sending teenage boys out against Rock and his men.