Jefferson reduced the size of the federal government numerous times, which exemplified his belief in upholding the power of the states. He also allowed more ordinary citizens to vote by eradicating property ownership as a qualification.
Election of 1800
President Jefferson believed in a "strict construction" view of the Consitution. This means that he conducted his duties as directed by the verbatim wording of the document. He did not believe in implied powers, which was deemed controversial in the Louisiana purchase (1803).
despite being controversial Jefferson approved the 1803 Louisiana Purchase from France. Napolean was fighting in Europe and saw no benefit in possessing land in the US, he also needed money, because of this he sold the land for 15 million dollars.
Lewis and Clark
In 1800, Jefferson ran against John Adams with Aaron Burr as his Vice Presidential candidate. This highlights the importance of the 12th Amendment because at the time the most votes won and they had tied. It took thirty-six ballots in the House of Representatives before Jefferson was named the winner.
In the final days of his presidency, Adams appointed many federal judges to fill positions created by the Judiciary Act of 1801. Democratic-Republicans were outraged by the appointment of these "midnight judges," so Madison did not deliver the forms. This created the case of Marbury vs. Madison, which ultimately outlined the powers of the Judicial Branch through John Marshal's constitutional judgment.
Jefferson believed in the importance of establishing an American presence in the new land from the Luisianna purchase before Europeans did. Because of this in 1804 president Jefferson appointed his personal secretary Meriwether Lewis, along with William Clark, as the leaders of a western expedition, dubbing it the Corps of Discovery.