Onto the bloody battleground of the Kansas Border Wars rides an ambitious group of West Point graduates, assigned to promote peace between the warring factions of the slavery debate. To succeed, they must reckon with John Brown, who will stop at nothing to win freedom for slaves. Starring Oscar winner Olivia de Havilland, "King of the Swashbucklers" Errol Flynn, and Ronald Reagan, playing the fated George Armstrong Custer.

In 1854, the United States Congress passed the Kansas-Nebraska Act, which answered the question of slavery in the western territories by giving their settlers the right to vote on it. Violent clashes became commonplace as Free-Soilers and proponents of slavery flooded Kansas in the effort to swing the vote. Santa Fe Trail tells the story of a group of West Point graduates sent to suppress the violence by standing between the warring parties, although some of the combatants, such as abolitionist John Brown, vowed to stop at nothing..not even death.