Undaunted Courage: Meriwether Lewis, Thomas Jefferson, and the Opening of the American West

by Stephen E. Ambrose

No man did more for human liberty than Thomas Jefferson, author of the Declaration of Independence and of Virginia’s Statute for Religious Freedom, among other gifts to mankind. Few men profited more from human slavery than Jefferson.

The language being recorded was Hidatsa. A native speaker would say a word to Sacagawea, who would pass it on in Hidatsa to Charbonneau, who would pass it on in French to Jessaume, who would translate it into English for the captains. MacKenzie thought Jessaume’s English ranged somewhere between inadequate and nonexistent, magnifying the chances for error.

The search for Lewis came about because the commanding general of the U.S. Army was secretly a Spanish spy, code name “Agent 13.”