History books cast William Clark as a wilderness-braving, 1800s action hero, a partner with Meriwether Lewis in the nearly two-and-a-half-year exploratory expedition that cleared the way for America’s westward expansion. But his ledger entries reveal another, less gallant side.

In a discussion of her new book, historian Jo Ann Trogdon examines Clark’s activities more than five years before his epic journey and presents evidence—gleaned from her examination of his leather-trimmed journal—that links him to a series of treasonous plots dubbed the “Spanish Conspiracy.” It involved corrupt officials who sought to line their pockets with Spanish money and convince American frontier settlers along the Mississippi River to break away from the U.S.

Watch at c-span.org