In the first half of the nineteenth century the United States government sponsored two highly significant exploring expeditions. From 1803 to 1806 Meriwether Lewis and William Clark led an expedition through the interior of North America to the Pacific coast. A little more than thirty years later Lt. Charles Wilkes of the United States Navy captained an oceanic expedition that produced the first clear evidence that Antarctica was a continent, charted hundreds of South Pacific islands, and mapped the northwestern coast of North America. Most Americans have heard of the exploits of Lewis and Clark, but few know about the four-year voyage of Wilkes and his squadron. Wilkes, who served in the navy for more than fifty years and faced two courts-martial for his headstrong actions and his unguarded opinions of his superiors, deserves more attention than he has received from scholars. He provides a fascinating example of nineteenth-century American...