MAP 7.4 U.S. Population Density in 1803 and the Louisiana Purchase
When the United States purchased Louisiana from France in 1803, much of the land to its east — the vast territory between the Appalachian Mountains and the Mississippi River — remained in Indian hands. The equally vast lands beyond the Mississippi were virtually unknown to Anglo-Americans, even after the epic explorations of Meriwether Lewis and William Clark. Still, President Jefferson predicted quite accurately that the huge Mississippi River Valley “from its fertility … will ere long yield half of our whole produce, and contain half of our whole population.”