Drums in the Deep South is an American Civil War war western film directed by William Cameron Menzies who was production designer of David O. Selznick's Gone With the Wind (1939) and also designed the cave sequences in Selznick's The Adventures of Tom Sawyer (1938). Based on a story by Civil War author Hollister Noble, the film was produced by an independent company King Brothers Productions, filmed in SuperCineColor and released by RKO Pictures in September 1951. B. Reeves Eason directed the second unit.
Plot
Best friends Clay Clayburn (James Craig) and Will Denning (Guy Madison) graduate from West Point and visit their friend and fellow graduate Braxton Summers (Craig Stevens) at his Georgia plantation in 1861. Clay had once loved Braxton's wife Kathy (Barbara Payton) and still does. When war is declared they soon find themselves fighting on opposite sides of the Civil War.
By 1864, Clay, now a field artillery major in the Confederate States Army, is renowned for accepting and surviving suicide missions. He is given another task: in order to delay General Sherman's March to the Sea, he is ordered to lead a party of men and their disassembled cannon inside caves that lead to the top of Devil's Mountain, where a battery of guns can destroy a railroad (running through nearby Snake Gap) and the Union troop and supply trains that travel it, buying time for the Confederacy. Devil's Mountain is coincidentally near Braxton's (who is now fighting elsewhere for the Confederacy) and Kathy's old plantation where Kathy remains with her uncle Albert (Taylor Holmes). Kathy agrees to monitor the activities of the Northern invaders and to signal Clay's men from her window through a mirror by day and a lantern by night. At one point, having been caught signaling to Clay by one of the Union soldiers, Albert mortally wounds him before being shot dead himself. Through her activities, Clay's men are notified of the arrival of two supply trains and destroy both of them.
Will, now a major himself, arrives on the field, but the Union artillery cannot achieve the elevation or range with their cannon to clear the Confederate guns at the top of the mountain. Inside the mountain, the Union infantry cannot find the path to the top and are delayed by Confederate snipers. As the railroad line has been blocked by two destroyed trains, Union headquarters send a Dahlgren gun manned by sailors and mounted on a flat car to wipe out the Confederates. Kathy supplies Clay with wire from her piano to reinforce the barrel of one of Clay's guns that, with a double charge and the maximum elevation, is able to destroy the naval gun and further block the railroad line.
Will has Union Army engineers mine the inside of the mountain with explosives that will blow up the mountain. However, Clay calculates that the explosion will send the cliff down over the railway line further blocking the Union's supplies. Kathy begs will that she be allowed to act as a mediator to convince Clay and his men to surrender, and Will agrees. As she traverses the caverns on the way to the top, Kathy is mistaken for a Union soldier and shot by one of Clay's soldiers. Bringing her to Clay, she repeats the Union offer of surrender as Clay nurses her wound. Ordering his men to escape Devil's Mountain, Clay picks up Kathy and begins making his way down. However, the powder is lit and Devil's Mountain explodes, seemingly killing Clay and Kathy.