The four Jennings brothers are Lawyers. When Al has a brother murdered, he goes after the murderer. He outdraws him but a witness says it was murder. Escaping the Sheriff he take refuge on a cattle ranch only to learn all the hands are rustlers. With a price on his head Al joins them and becomes an outlaw. His fame grows as does the reward for his capture.

In 1863, in Tennessee, as the battle between the States rages, the wife of Confederate officer Major Jennings gives birth to her fourth son Al in a small abandoned cabin. Mirroring the turbulent times in which he was born, Al grows up quick-tempered and prone to violence in Coldwater, Kansas. Although he follows his older brothers and father into the respectable practice of law, Al is not beyond provoking a brawl in open court when angered. Eventually, with Judge Jennings' consent, Al and his brother Frank decide to leave Coldwater and join their brothers John and Ed in Woodward, in the Oklahoma Territory. On the journey, Al comes to the aid of Margo St. Claire when she is trapped on a runaway buckboard. Margo tells Al she is also traveling to Woodward for a brief visit with her uncle, Bob Kyle. Upon arriving in the town, Al and Frank discover that Ed is in the middle of a water rights case, defending Kyle from accusations of non-payment by known swindler Bill Mertz. The next day in court, Al runs into Margo and flirts with her. Although charmed, she tells him she is returning home to New Orleans shortly and Al promises to visit her there. Later, Al interrupts the court proceedings when the opposing counsel, Tom Marsden, maligns Ed. A fight breaks out, but once Al is subdued, Ed eventually wins his case, incensing Mertz and Marsden. The next evening Mertz sees Ed and Al in the local saloon playing cards and summons Marsden, who confronts and kills Ed. The sheriff promptly arrests Marsden and assures a furious Al that justice will prevail in court. The next day, as Judge Jennings joins his grieving sons, the sheriff regretfully informs them that Marsden is out on bail. Angry, Al rides out to Marsden's ranch, determined to get a signed confession from him. Marsden stalls, then draws his gun, but Al is quicker. Mertz, witnessing the killing, hurries away to report to the sheriff, blaming Al. Al flees with Frank and together they outwit a posse before riding into the Diamond B cattle ranch, which they soon discover is a cover for outlaw Fred Salter and his gang. Salter blackmails Al and Frank into joining the gang, threatening to turn Al in for the posted $1,000 bounty. Al quickly becomes the head of the gang, which holds up banks, stagecoaches and trains. When the bounty on Al goes up to $20,000, the brothers decide they should break away from Salter and escape to Louisiana. Under the name of Thompson, the Jennings use their abundant means to begin a cotton brokerage and go straight. Al looks up Margo and confesses his past, which she forgives, and soon the couple is engaged. One day a railroad detective, Dan Hanes, recognizes the Jenningses and plots to have them kidnapped and taken back to Oklahoma Territory. With Margo's help, however, Al and Frank escape. Knowing they can not stay in Louisiana, they return to Salter's ranch to pull one final job to get enough money to leave the country. Mrs. Salter, greedy for the reward money, informs the marshal about the robbery plans. A posse captures all the gang except the Jenningses, who cross the state line into Arkansas before Al is thrown from his horse, breaking his leg. The marshal disregards the state line and arrests the brothers. Back in Oklahoma, Judge Jennings defends his sons in court but the trial judge bullies the split jury into convicting the Jenningses. Frank is sentenced to five years and Al to life. Five years later, however, the irregularities of Al's arrest and trial gain him release and eventually a pardon from President Theodore Roosevelt.