What was the primary objective of the Lewis and Clark expedition?

The primary objective of the Lewis and Clark expedition was to explore the newly acquired Louisiana Territory and find a route to the Pacific Ocean. This expedition, officially known as the Corps of Discovery, was commissioned by President Thomas Jefferson following the 1803 Louisiana Purchase, which doubled the size of the United States and opened a vast expanse of territory for exploration and potential settlement.

Jefferson aimed not only to map the geography of the region but also to gather scientific knowledge about the flora and fauna, as well as to establish relations with Native American tribes encountered along the way. The ultimate goal of finding a water route to the Pacific Ocean was significant for facilitating trade and westward expansion. The expedition successfully traveled from St. Louis, Missouri, to the Pacific Northwest, providing valuable information about the western territories which would influence the United States' growth and development.

Other options, while they may contain elements related to exploration and trade, do not capture the comprehensive goals of the expedition. The objectives were much broader than just establishing trade with Native Americans or mapping the Atlantic coastline, and the search for gold in California was not part of the Lewis and Clark expedition, which took place before the gold rush began.