Originally being a mechanic for the Army before the war, and having worked in an artillery regiment for several years, John Jackson "Schmitty" Smith joined Sgt. Glenn "Hawk" Hawkins's squad (consisting of Roland Roger, Alvin "Brooklyn" Bloomfield, and Stephen Kelly) as a replacement for Pvt. Victor "Vic" Denley, who was killed in Sicily. He is a bit "doughy", as he did not see much prior combat and did mechanical work instead.
He is first seen as a Private in the mission, "The Great Crusade", where he is treated like other replacements by Brooklyn, who was one of the original men of the squad, and who saw Denley get killed, himself. While they approached Omaha Beach on D-Day, the landing craft they were riding in gets hit, and they are forced to ride a canvas raft all the way to the beach. Schmitty does not get a specific role until much later, when they reach some German bunkers and a Flak 88 they could use to blow them up. However the 88 was busted, so Schmitty proved his worth by fixing it. He succeeds, and Roger is able to use it to blow up the opposing bunkers.
He does not join the squad in Maubeuge for unknown reasons.
He joins up with the squad again in "An Easy Detail" in Mons, just in time for Roger (now a Sergeant) to get out of the hospital. He inquires what happened, and is told that Roger got hit by a mortar round before Hawk rides up and tells the squad what they had to do. Later, after they take a mill, the squad is called upon to take out some Flakvierlings giving trouble to air support. Schmitty points out that the whole regiment is counting on this, and that they are sending five men to disable the AA guns, which is brushed off by Hawk. He later bears witness to Hawk getting wounded (for the third time) by MG42s in a camp on an overlooking hill. Unlike the others, he is slightly skeptical of Hawk's chances, and watches as Hawk is rolled out by a jeep.
Schmitty is promoted to Corporal by the time of "Crucifix Hill". He, Roger, and Kelly (now also Sergeant) are among the many soldiers on canvas rafts crossing the river. He, Roger and Kelly are the only survivors of Nebelwefer fire, and they help reinforce the other soldiers on the hill. They take out three Flakvierlings and the Nebelwefers before being called to a village near the Siegfried Line. Schmitty gives Brooklyn's sentiments during this time: The United States Army is made up of the Big Red One and two million replacements. Kelly gives his agreement on the matter.
Schmitty does not have a specific role in the village, but he does help the others on the way to the Siegfried Line. He sadly bears witness to Brooklyn's death, but continues on with the rest of the squad. They eventually encounter two V2 rockets, and after Roger sets the charges, Smith blows them, and the rockets, as well as some unfortunate Panzers, get blown up. Smith survives the campaign and celebrates with Kelly on their victory.
- The Call of Duty 2: Big Red One instruction booklet says that he was 28 years old "when the war started", but it does not specify whether that refers to the 1939 invasion of Poland or the 1941 attack on Pearl Harbor.
- Call of Duty 2: Big Red One character biography on Smith.