"If we do in fact 'remember the Alamo,' it is largely thanks to one person who witnessed the final assault and survived: the commanding officer's slave, a young man known simply as Joe. What Joe saw as the Alamo fell, recounted days later to the Texas Cabinet, has come down to us in records and newspaper reports. But who Joe was, where he came from, and what happened to him have all remained mysterious until now. In a remarkable feat of historical...