Hoping to increase its box-office allure by adopting the title of a popular song, Deep in the Heart of Texas (clap!clap!clap!clap!) was the first Johnny Mack Brown western of the 1942-43 season. The plot concerns a group of insurrectionists who intend to keep Texas separate from the rest of the USA.
A ranch owner gives the Cheyenne Kid $1000 and sends him off to buy cattle. At the same time he fires a ranch hand and that hand rides ahead and alerts Jeff Baker about the $1000. Bakers' henchman are too late to get the Kid but they kill the rancher paid by the Kid. The Sheriff then arrests the Kid claiming he murdered the rancher to get the money back and that Baker said he then lost it at his gambling table.
In 1911, minor stage comic, Vernon Castle meets the stage-struck Irene Foote. A few misadventures later, they marry and then abandon comedy to attempt a dancing career together. While they're performing in Paris, an agent sees them rehearse and starts them on their brilliant career as the world's foremost ballroom dancers. However, at the height of their fame, World War I begins.
When the miners of Roaring Camp become Godfathers to a motherless baby, they name the boy Luck and promise to set aside money for him from their diggings. But when they strike it rich the money is gambled away instead.
The Indians need the Buffalo to survive and the Government has promised to keep the herds free from hunters. But Carter, of Carter and Barton, just signed a big contract for furs and Buffalo meat so they want the herds. The only way they can get them is to rile the Indians up enough to go on the warpath and break the treaty. After the trouble starts, the Indians get the Colonel's daughter and hold her prisoner. Written by Tony Fontana
Bill travels to a new state after the outlaw Scarface saves him from a lynch mob. There he takes a job on the Barton ranch and joins in the fight against gang leader Larkin. Finding a wounded Scarface he helps him recover. Arrested by Larkin's stooge Sheriff, and with another lynch mob after him, he once again needs Scarface's help.
Twelve renegades dressed as Indians kill the parents of two brothers. The brothers who have similar birth marks then separate. Ten years later a man known as the Rawhide Terror is murdering the renegades who are now town citizens. Everyone is after the Rawhide Terror and the two brothers are destined to meet again.
While building an irrigation system for a Southwestern desert community, an engineer vies with a local cowboy for the affections of a rancher's daughter.
Outlaw Black Deering leads a band of desperadoes, but decides to give up the bandit life. Agreeing to go on one last job with his gang, he is captured when his henchman Jordan betrays the gang for the reward. Deering escapes and determines to avenge himself on Jordan.