Marvin Ivan "Buck" Barrow (March 14, 1903 – July 29, 1933) was a member of the Barrow Gang. He was the older brother of the gang's leader, Clyde Barrow. He and his wife Blanche were wounded in a gun battle with police four months after they joined up with Bonnie and Clyde. Marvin died of his wounds.
Ivan Barrow was born in Jones Prairie, Marion County, Texas, the third child of Henry and Cumie Barrow. An aunt, watching the little boy "running around acting like a horse,"gave him the nickname Buck  He stopped going to school around age 8 or 9, enjoying fishing and hunting far better.
In the early 1920s the older Barrow children left the family farm one by one, to marry and start careers in the city of Dallas. At 18 or 19 Marvin too went to Dallas, ostensibly to work for his brother repairing cars, but he quickly became part of the West Dallas petty-criminal underworld. His sister Marie, barely school age when she and her parents moved to the West Dallas campground, remembered watching him put spurs on roosters for cockfighting, and his pit bull, which tore off the back of her dress. He married twice and divorced twice during this time, and had three children by those marriages. Just before Christmas 1926 Marvin, 23, and Clyde, 17, were arrested with a truck full of stolen turkeys they intended to sell for the holidays. Marvin took the rap for himself and his brother and went to jail for a week, but the turkey adventure was an ironic joke, as by now Marvin was making ends meet by stealing automobiles in cities all over Texas and selling them for a comfortable $100 or so to fences out of state.
On November 11, 1929, Barrow met Blanche Caldwell in an unincorporated part of Dallas County called West Dallas. They fell in love almost immediately.
On November 29, 1929, several days after meeting Blanche, Marvin Barrow was shot and captured following a burglary in Denton, Texas. He was tried, convicted, and sentenced to four years in the Texas State Prison System. On March 8, 1930, however, Barrow escaped from the Ferguson Prison Farm near Midway, Texas. He simply walked out of the prison, stole a guard's car, and drove to his parents' place in West Dallas where Blanche was living.
In interviews with author/historian John Neal Phillips, Blanche was frank about the fact that she not only knew of Marvin's escape, but that she hid with him and actually staged robberies with him. The notion that Blanche did not know until later that Marvin was an escaped convict was fabricated by the Barrow family and Blanche herself as a means of convincing Missouri State authorities to reduce her prison sentence following her capture in July 1933.
On July 3, 1931, Blanche and Marvin were married in Oklahoma. Blanche was not interested in pursuing a criminal career. She and other members of the Barrow family convinced Buck to turn himself in to Texas prison authorities and complete his sentence. Two days after Christmas 1931 his mother and his wife drove him to the gate of Huntsville penitentiary, where he told surprised prison officials that he had escaped almost two years before and needed to resume his sentence. They welcomed him in.
During his two years at Huntsville Marvin sent repentant letters home, written for him by fellow prisoners. Before he had served two years of his six-year sentence he was abruptly pardoned, partly as part of Texas governor Ma Ferguson's plan to decrease prison crowding and partly due to the lobbying efforts of his wife and his mother.
Upon his release, March 22, 1933, Marvin Barrow, in the company of Blanche, joined his younger brother Clyde, Bonnie Parker, and W. D. Jones in Joplin, Missouri where he participated in several armed robberies.
On April 13, 1933, Marvin, Clyde, and W.D. Jones participated in a shootout with law enforcement officers at Joplin, Missouri. Two officers, Newton County Constable Wes Harryman and Joplin City Motor Detective Harry McGinnis, were killed.
On June 23, 1933, Marvin and W. D. Jones killed Alma, Arkansas City Marshal Henry D. Humphrey during a gunfight on the road between Alma and Fayetteville. Clyde Barrow was not involved in the Humphrey killing.
On July 19, 1933, Marvin was mortally wounded in the head during a shootout at the Red Crown Tourist Court at Platte City, Missouri. The bullet opened up a large hole in Marvin's forehead that exposed his brain and caused severe loss of blood. Blanche was also wounded in the same gunfight. She and her husband escaped, however, along with Bonnie, Clyde, and W. D. Jones. Despite his ghastly head wound, and loss of blood, Marvin was sometimes fully conscious, and talked and ate.
On July 24, Marvin, near death, was wounded in the back during yet another shootout, this time near an abandoned amusement park between Redfield and Dexter, Iowa. Bonnie, Clyde, and W. D. Jones, all wounded in the same gunfight, escaped. Marvin and Blanche, though, were captured.
Blanche survived her wounds, although losing sight in one eye. Extradited to Missouri, she was tried for the attempted murder of Sheriff Holt Coffey at Platte City. She was convicted and sentenced to ten years in prison.
His doctors commented in their report on how clean Marvin's head wound was, given the circumstances. Bonnie and Clyde had poured hydrogen peroxide into the head wound, cleaning it. On arrival Marvin was generally lucid and told doctors that aspirin helped the pain in his head and the only real pain he felt was from his other gunshot wounds, particularly the one in his back. That bullet, doctors discovered, had entered his back, ricocheted off a rib and lodged in his chest wall close to the pleural cavity. Because he was in such a weakened state—his limbs had grown paralyzed from another bullet wound and his temperature would not lower from 105—his doctors expected he would develop pneumonia from the surgery on his chest. They predicted either that or infection of his brain from the head wound would kill him in a few days.
Lawmen visited him in the hospital to get his final statements. Though doctors kept him numb with opiates, they also injected him with stimulants at least twice, that he might answer questions. "Due to the lack of medical attention," an interrogator noted, "the wound in Barrow's head gave off such an offensive odor that it was with utmost difficulty that one could remain within several feet of him." He agreed with Deputy Red Salyers that he had shot and killed Marshal Humphrey in Arkansas. He was able to chat with the doctor, who asked him, "Where are you wanted by the law?" "Wherever I've been," replied Marvin. 
When word of Marvin's dire situation reached Texas, Dallas County Sheriff R.A."Smoot" Schmid wrote a letter of introduction to the local authorities for Marvin and Clyde's mother Cumie, and a deputy sheriff provided money to help her cover the costs of the 36-hour drive to Iowa by Model-A. She and her youngest son LC arrived for Marvin's last conscious hours. As his pneumonia strengthened he became delirious and finally slipped into a coma, from which he did not wake.
Henry and Cumie Barrow put off buying a gravestone for Marvin . They were sure Clyde would follow him into death any day, and whether for practical or loving reasons or a mix of both, decided to wait for Clyde. Clyde liked the idea and suggested the epitaph to go over himself and his brother: "Gone But Not Forgotten."
On Marvin and Clyde's shared gravestone, Marvin's year of birth is incorrect. His mother gave the stone cutters their sister Nell's birth year for him. However, she had recorded the birth dates of all her children in the family Bible; there, Marvin's birth date is 1903.