Young Audie Murphy (Gordon Gebert) grows up in a large, poor sharecropper family in Texas. His father deserts them around 1939–40, leaving his mother (Mary Field) barely able to feed her nine children. As the eldest son, Murphy works from an early age for his neighbor, Mr. Houston, a local farmer, to help support his siblings. Murphy and Mr. Houston are interrupted while working and listen to the radio announcement about the Attack on Pearl Harbor. When his mother dies in 1941 Audie becomes head of the family. His brothers and sisters are sent to an elder sister, Corrine. Murphy is then convinced by Mr. Houston to enlist in the military to support himself.
Murphy is rejected by the Marines, the Navy, and the Army paratroopers due to his small size and youthful appearance. Finally, the Army accepts him as an ordinary infantryman. After basic training and infantry training, Murphy is shipped to the 3rd Infantry Division in North Africa, as a replacement. Because of his youthful looks, he endures jokes about "infants" being sent into combat. His squad mates include: Johnson, a man who claims to be a womanizer; Brandon, a man who ran out on his wife and daughter; Kerrigan a man who jokes at unusual times; Kovak a Polish immigrant who wants to become an American citizen; Swope ( called "Chief" by his squad mates) a Native American who smokes cigars a lot, and Valentino who has relatives in Naples.
After the 3rd Infantry Division lands in Sicily, Murphy and his men come under attack by a German machine gun position. Murphy and his men assault the position and kill the Germans. After fighting in Sicily, Murphy is then promoted to corporal. After Sicily, Murphy and his squad receive a new platoon leader, Lt. Manning. During a diversionary attack on German forces, Lt. Manning is wounded and Sgt. Klasky, his platoon sergeant, dies. This results in Murphy taking command of the platoon. After proving himself in leading his platoon while fighting in Italy, he is then promoted to sergeant. Murphy and his men are then sent to Naples on R&R.
Murphy and his men later take part in Operation Shingle. After landing on the beach, Murphy and his men fight around an abandoned farmhouse. This battle results in Lt. Manning, Kovak, and Johnson being killed. After the Allied breakout of Operation Shingle, Murphy eventually receives a battlefield commission in the rank of second lieutenant.
The action for which Murphy was awarded the Medal of Honor is depicted near the end of the film. In January 1945, near Holtzwihr, France, Murphy's company is forced to retreat in the face of a fierce German attack. However, Murphy remains behind, at the edge of a forest, to direct artillery fire on the advancing enemy infantry and armor. As the Germans close on his position, Murphy jumps onto an abandoned M4 Sherman tank (he actually performed this action atop an M10 tank destroyer) and uses its .50-caliber machine gun to hold the enemy at bay, even though the vehicle is on fire and may explode at any moment. Although wounded and dangerously exposed to enemy fire, Murphy single-handedly turns back the German attack, thereby saving his company. After a period of hospitalization, he is returned to duty. The film concludes with Murphy's Medal of Honor ceremony shortly after the war ends, as Murphy remembers Kovak, Johnson, and Brandon, who were killed in action.
When Universal-International picked up the film rights to Audie Murphy's book, he initially declined to play himself, recommending instead Tony Curtis, with whom he had previously worked in three Westerns, Sierra, Kansas Raiders and The Cimarron Kid. However, producer Aaron Rosenberg and director Jesse Hibbs convinced Audie to star in the picture, despite the fact the 30-year-old Murphy would be portraying himself as he was at ages 17–20.
The picture was filmed at Fort Lewis and Yakima Training Center, near Yakima, Washington with actual soldiers. Murphy received 60% of the $25,000 the studio paid for the rights, as well as $100,000 and 10% of the net profits for starring and acting as a technical advisor.
Originally, several generals who served in World War II were considered to perform the voiceover opening for the movie, among them Maxwell D. Taylor and Omar Bradley, until General Walter Bedell Smith was finally chosen.
The film's world premiere was held at the Majestic Theatre in San Antonio, Texas on August 17, 1955. The date of the premiere was also the tenth anniversary of Murphy's army discharge at Fort Sam Houston in San Antonio.
The film was a huge commercial and critical success, and advanced Murphy's film career. He had a percentage of the profits and it was estimated the actor earned $1 million from the film. The movie also popularized a term for U.S. Army foot soldiers, "dogface". The film included the 3rd Infantry Division song, "Dogface Soldier", written by Lieutenant Ken Hart and Corporal Bert Gold.
Many of the battle scenes were reused in the Universal film The Young Warriors.
Murphy tried to make a sequel called The Way Back dealing with his post-war life but could never get a script that could attract finance.