Directed by Andrew V. McLaglen, The Undefeated is a 1969 western starring John Wayne, Rock Hudson, Roman Gabriel, and Antonio Aguilar. Wayne plays ex-Union Colonel John Henry Thomas, who is driving a team of horses across the Rio Grande to Mexico for sale. Hudson, meanwhile, plays ex-Confederate Colonel James Langdon, who is leading a contingent of displaced Southerners to serve Emperor Maximilian during the French Intervention in Mexico. Thomas and his men ultimately comes to the aide of their former enemies, exchanging their horses as ransom after Langdon's company is taken hostage by Mexican Republican forces. This behind-the-scenes footage captures the production filming on location in Mexico. In addition to shots of the cast and crew, the film also shows the immense coordination of horses for particular scenes.