When Robert Cavelier, sieur de La Salle, landed on the Texas coast in 1685, bent on founding a French colony, his enterprise was doomed to failure. Not only was he hundreds of miles from his intended landfall-the mouth of the Mississippi-but his supply ship, Aimable, was wrecked at the mouth of Matagorda Bay, leaving the colonists with scant provisions and little protection against local Indian tribes. In anger and disgust, he struck out...