The Louisiana Purchase and the journey of Lewis and Clark’s Corps of Discovery captured the imagination of many, who dedicated themselves to the economic exploitation of the western lands and the expansion of American… In 1803, Thomas Jefferson appointed Meriwether Lewis to organize an expedition into the Louisiana Territory to explore and map the area but also to find an all-water route from the Missouri River to the Pacific Coast.

In the South, the Adams-Onís treaty legally secured Florida for the United States, though it did nothing to end the resistance of the Seminoles against American expansionists. At the same time, the treaty frustrated those Americans who considered Texas a part of the Louisiana Purchase.

Corps of Discovery — the group led by Meriwether Lewis and William Clark on the expedition to explore and map the territory acquired in the Louisiana Purchase. Liberty Party — a political party formed in 1840 by those who believed political measures were the best means by which abolition could be accomplished. Barnburners — northern Democrats loyal to Martin Van Buren who opposed the extension of slavery into the territories and broke away from the main party when it nominated a pro-popular…. Compromise of 1850 — five separate laws passed by Congress in September 1850 to resolve issues stemming from the Mexican Cession and the sectional crisis.