Captain Clark shifted his stance uncomfortably. The French trader, Charbonneau, and his wife, Sacagawea, stood before him offering their services as interpreters and guides through the unchartered territory of The Louisiana Purchase. But Sacagawea was just a young girl, Clark silently observed. She couldn't be more than fifteen years of age, and she was obviously expecting a child Besides, Clark knew that Charbonneau had a reputation for being...