In 1816, Mordecai Lewis, a veteran of Andrew Jackson's Indian campaigns and battles against the British, moves his family into the western Tennessee canebrakes. But Mordecai is not satisfied with farming, and with his sons Michael and Andrew, he leads a foray into Spanish-held Texas to hunt wild horses and return the mustang herd to sell in Tennessee. Unfortunately, a bloody skirmish along the way leaves Mordecai dead, and his sons find their way back to their Tennessee farm. Five years later, after the Spanish government in Mexico City has agreed to permit three hundred American families to settle in Texas, the Lewis brothers ride to the frontier town of Natchitoches, Louisiana, intending to be part of the new American colony. But they are considered interlopers and horse thieves, and are dogged by a patrolled by the same ruthless Spanish officer who killed their father.