Nevertheless, Adams did attempt to seek revenge. During his last days as president, he created several new judiciary positions and filled the posts with Federalist supporters. Jefferson and his secretary of state, James Madison, refused to honor the appointments of these “midnight justices.”
One of the justices, William Marbury, sued Madison for his appointment, and the case eventually reached the Supreme Court in 1803. Chief Justice John Marshall, a die-hard Federalist, sympathized with Marbury but believed that Jefferson would never adhere to a ruling against Madison. Therefore, Marshall ruled in Marbury v. Madisonthat although Marbury was entitled to the judgeship, the Supreme Court could not force the president to give it to him.
Although the Judiciary Act of 1789 had given the Supreme Court this power, Marshall’s ruling effectively declared that act unconstitutional. Marshall thus simultaneously gave Jefferson his victory and strengthened the Supreme Court with the power of judicial review—the right to declare Congress’s laws unconstitutional.
Despite his belief in limited government, Jefferson seized the opportunity in 1803 to buy the vast expanse of the Louisiana Territory from France. France had reacquired the territory from Spain in 1801, but Napoleon’s costly war in Europe forced him to consider selling the land. Jefferson, fearing that the French would revoke U.S. access to the major Mississippi River port of New Orleans, sent James Monroe to Paris to offer $10 million for New Orleans alone. Napoleon, however, in need of money, offered the entire Louisiana Territory for $15 million, and Monroe agreed.
Although the Constitution said nothing about the purchase of new lands, Jefferson swallowed his pride and accepted the Louisiana Purchase. The new territories included present-day Louisiana, Arkansas, Missouri, Minnesota, North Dakota, South Dakota, Nebraska, and Kansas, as well as parts of Montana, Wyoming, Colorado, and Oklahoma—all for a mere $15 million. Not only was the purchase the best real estate deal in history by far, it also established a precedent for purchasing lands to expand the United States farther westward.
In 1804, Jefferson dispatched his secretary Meriwether Lewis and army captain William Clark to explore the Louisiana Territory. Lewis and Clark’s famous two-year expedition to the Pacific helped publicize the bountiful new lands. In addition to finding countless natural wonders in the West, the pair traversed the fertile Mississippi Valley, which Jefferson hoped would become the heartland of an agrarian United States.