Book excerpt: "Thomas Jefferson's Corps of Discovery included Captains Lewis and Clark and a crew of 28 men to chart a route from St. Louis to the Pacific Ocean. All the crew but one volunteered for the mission. York, the enslaved man taken on the journey, did not choose to go. Slaves did not have choices. York's contributions to the expedition, however, were invaluable. The captains came to rely on York's judgement, determination, and peacemaking role with the American Indian nations they encountered. But as York's independence and status rose on the journey, the question remained what status he would carry once the expedition was over. This is his story."--Provided by publisher.