In 1804 Thomas Jefferson made one of his most significant contributions as president when he

Purchased the Louisiana Territory.

Explanation:

Jefferson's most significant accomplishment as president was the Louisiana Purchase. In 1803, he acquired land stretching from the Mississippi River to the Rocky Mountains from cash-strapped Napoleonic France for the bargain price of $15 million, thereby doubling the size of the nation in a single stroke.

Purchased the Louisiana Territory.

answer: the correct answer is d. a christian revivalist movement in the u.s. during the early 19th century

explanation: the second great awakening was lead by the preachers of baptist and methodist congregations in order to gain support for the protestant religion from the 1790's to 1840's