Thomas Jefferson instructed Meriwether Lewis to gather detailed information about the Native Americans living in the Louisiana Territory during the Lewis and Clark Expedition for several reasons.
Firstly, Jefferson was interested in promoting westward expansion and believed that by gathering information about the inhabitants of the land, the United States would be better equipped to establish diplomatic relations and peacefully coexist with the Native American tribes. This was particularly important as the Louisiana Territory was home to numerous Native American tribes with different cultures, languages, and beliefs.
Secondly, Jefferson wanted to understand the natural resources of the Louisiana Territory, including the plants, animals, and minerals that could be used for trade, agriculture, and industry. This information would help the United States to develop and utilize these resources for its own benefit.
Thirdly, Jefferson believed that understanding the geography of the Louisiana Territory was essential for the United States to expand its borders and secure its western frontier. By exploring the territory and gathering information about its landscape, rivers, and natural features, the United States would be better equipped to navigate and defend its new territories.
Overall, Jefferson wanted to gain as much information about the Louisiana Territory as possible to facilitate westward expansion, understand the natural resources and geography of the land, and establish peaceful relations with the Native American tribes who lived there.