At the start of the Civil War, the people of Lebanon Valley try to stay neutral and secede from the state of Mississippi. Led by Hoab Dabney (Ward Bond), and with the help of his friend Tishomingo (Boris Karloff), a loyal Native American, they vow to protect the valley against the Confederate army. News publisher Keith Alexander (Van Heflin) hopes to win the affections of Hoab's daughter Morna (Susan Hayward) and joins the cause. Morna originally plans to marry Confederate officer Clay Maclvor (Whitfield Connor), but those plans change after he is injured in a riding accident. But what Morna doesn't know is that Clay actually loves her sister Aven (Julie London) and they elope. As Keith continues to pursue Morna, the Confederate army led by Clay launches an attack on the valley and the defenders are defeated. In a final showdown in a swamp, Keith kills Clay and he is finally reunited with Morna.