What was the main purpose of the Lewis and Clark expedition?

The Lewis and Clark expedition, officially known as the Corps of Discovery, primarily aimed to explore and map the newly acquired western territory following the Louisiana Purchase in 1803. This significant land acquisition doubled the size of the United States and required a thorough understanding of the geography, resources, and potential for settlement in the region.

The expedition produced invaluable maps and detailed accounts of the land's features, which were essential for future exploration and settlement. While establishing trade with tribes, finding a route to the Pacific Ocean, and gathering scientific data about flora and fauna were also important aspects of the journey, they were secondary to the overarching goal of thoroughly exploring and documenting the new territory. Thus, the correct answer highlights the expedition's primary mission of exploration and mapping, making it a foundational event in American history.