Spanish, British, and French explorers reached the Pacific Northwest before Meriwether Lewis and William Clark. The American captains benefited from those predecessors, even carrying with them copies of their published accounts. James Cook, George Vancouver, and Alexander Mackenzie--and to a lesser extent fur traders John Meares and Robert Gray--directly and indirectly influenced the expedition. Based on new material as well as revised essays from popular history journals, Lewis and Clark Reframed examines several curious and seemingly inexplicable aspects of the journey after the Corps of Discovery crossed the Rocky Mountains.

The captains' journals demonstrate that they relied on Mackenzie's 1801 Voyages from Montreal as a trail guide. They borrowed field techniques and favorite literary expressions--at times plagiarizing entire paragraphs. Cook's literature also informed the pair, and his naming conventions evoke fresh ideas about an enduring expedition mystery--the identity of the two or three journalists whose records are now missing. Additional journal text analysis dispels the notion that the captains were equals, despite expedition lore. Lewis claimed all the epochal discoveries for himself, and in one of his more memorable passages, drew on Mackenzie for inspiration. Parallels between Cook's and other exploratory accounts offer evidence that like many long-distance voyagers, Lewis grappled with homesickness. His friendship with Mahlon Dickerson lends insights into Lewis's shortcomings and eventual undoing. As secretary of the navy, Dickerson drew from Lewis's troubled past to impede the 1840s ocean expedition set to emulate Cook and solidify America's claim, through Lewis and Clark, to the region.