Thomas Jefferson

Map of Lewis and Clark's trail, by Bradford and Inskeep, Philadelphia, 1814
Courtesy of Missouri Historical Society

In 1800 Spain restored the Louisiana Territory to France, and Thomas Jefferson learned that the territory could be acquired. But Jefferson believed in a strict interpretation of the Constitution and was troubled that it contained no authorization for the federal government to acquire land. He faced one of the most difficult questions presidents encounter: When is it right to exceed the authority of the presidency for the good of the country?

Jefferson resolved that a president must seize an opportunity that advances the nation, and in 1803 he approved the Louisiana Purchase for $15 million, doubling the area of the United States.

Lewis and Clark compass
In 1803 Thomas Jefferson organized an expedition, headed by Meriwether Lewis and William Clark, to explore the Missouri River and routes to the Pacific Ocean. The Louisiana Purchase made the journey more critical. In the spring of 1804, the Corps of Discovery set out from St. Louis to survey the Northwest.

This pocket compass used by William Clark is one of the few surviving scientific instruments from the expedition. The brass-and-silver compass set in a mahogany box was made by Thomas Whitney of Philadelphia.

Copy of the letter of credit from Thomas Jefferson authorizing Meriwether Lewis to charge expedition expenses to the federal government.
Courtesy of Missouri Historical Society