In the early 1840s, cattle baron Devereaux Burke (Clark Gable) is tasked by President Andrew Jackson (Lionel Barrymore) with an important diplomatic mission. Devereaux must convince soldier Sam Houston (Moroni Olsen) to help bring about the addition of Texas to the union. Along the way, Devereaux battles a pair of senators (Broderick Crawford, Ed Begley) who would rather create their own republic, and locks horns with a feisty newspaper reporter, Martha Ronda (Ava Gardner).