Samuel Lewis & Aaron Arrowsmith, Louisiana (1804)

At the time of the Louisiana Purchase in 1803, the geography of the West was largely a mystery, known mainly through the reports of Indigenous Peoples, traders, and explorers. As James Akerman and Robert Karrow point out in their book, Maps: Finding Our Place in the World, this lack of knowledge is evident in Samuel Lewis and Aaron Arrowsmith's map of the Louisana Territory, which was featured in their New and Elegant Atlas for 1804. Although Arrowsmith and Lewis based their map upon the best information at hand, there are several errors and omissions. For example, there is only one western mountain range, named the Stony Mountains (later the Rocky Mountains), and it is too far west; the Missouri River is drawn too far south; the Colorado River is missing entirely, still awaiting discovery by the United States; and the entire continent is far too short.