A comprehensive A-to-Z reference to mark the 200th anniversary of the Lewis and Clark expedition. On November 30th, 1803, France formally transferred 828,000 square miles to the United States in exchange for $15 million. This land, the Louisiana Purchase, doubled the size of the nation. While negotiations for this deal had been going on, Thomas Jefferson had already begun thinking about a transcontinental expedition to explore the lands west of the Mississippi. Besides the commercial and scientific benefits of such an exploration, there was the issue of asserting America's sovereignty over the new territory. Meriwether Lewis and William Clark were hired to undertake this journey. The Corps of Discovery, as the group is often referred to, kept detailed journals on the flora and fauna they observed, and members of their team were also the first non-Indians to make contact with a number of tribes. Sacagawea, the Shoshone wife of French-Canadian trapper Toussaint Charbonneau, served as their guide and interpreter for much of the trip. This book provides a complete reference to this great American expedition, covering all major elements from the preparatory work initiated by President Thomas Jefferson in 1801 to the corps's return from the Pacific Ocean in 1806.