In 1528, a mission set out from Spain to colonize Florida. But the expedition went horribly wrong: Delayed by a hurricane, knocked off course by a colossal error of navigation, and ultimately doomed by a disastrous decision to separate the men from their ships, the mission quickly became a desperate journey of survival.

Of the three hundred men who had embarked on the journey, only four survived--three Spaniards and an African slave. This tiny band endured a horrific march through Florida, a harrowing raft passage across the Louisiana coast, and years of enslavement in the American...