After the tragic Northfield, Minnesota robbery, in which several members of their gang are killed, the outlaw James brothers split up and Frank disappears to the Missouri countryside. There, using the name Ben Woodsen, he farms the land with his friends, Pinky and Clem, the son of one of the gang members. One day, Frank learns that his brother Jesse has been shot in the back by one of the Ford brothers, who have been sentenced to hang for their crime. Frank is resolved to let the law deal with the Fords until he reads that they have been pardoned and awarded money for their cowardly crime. Determined to exact justice for the murder of his brother, Frank rides after the Fords, who hastily depart for the West. To fund his crusade, Frank robs the railroad express office, rationalizing that it was railroad money that killed his brother. Frank's plans go awry, however, when Clem appears and insists that he join Frank. In the chaos, the watchman is killed and Frank is accused of the murder. In retaliation, McCoy, the head of the railroad, offers a reward for Frank, and his henchman, George Runyan, follows the Ford boys West, knowing that Frank will not be far behind. In Denver, Frank and Clem fabricate the story of Frank's demise, which is picked up by aspiring young newspaper reporter Eleanor Stone and printed in her father's paper. Meanwhile, Frank tracks down the Fords and in a frantic pursuit, Charlie Ford falls from a cliff and dies. While Frank is out of town, Runyan appears and identifies Ben Woodsen as Frank James. After eluding Runyan, Frank is about to ride after Bob Ford when Eleanor informs him that Pinky has been arrested for the freight office robbery and sentenced to hang. Torn between avenging his brother's murder and returning to Missouri to save his friend, Frank's conscience wins out and he rides to Missouri, where he is arrested and put on trial for murder. Frank's old friend, Major Rufus Todd, the town newspaper editor, defends him by casting the trial in terms of a war between the railroad and the farmers, the North and the South. Just as the jury, composed of Southern farmers, finds Frank innocent, Bob Ford appears and runs from the courtroom. In his flight, he kills Clem, but the boy fatally wounds Ford. With his brother's death avenged, Frank begins life anew.