What did Jefferson do as president?

Answer 1

In his first term of presidency Jefferson bought the Louisiana Purchase from France, doubling the size of the US. Next Jefferson sent Meriwether Lewis and William Clark on a quest to find the Pacific Ocean in 1803-1806. Jefferson also invented the moldboard plow, which was a great improvement on the already standard farming plow; the wheel cipher, and developed his own design on the concept of the spherical sundial. He was the first man to say that tomatoes weren't poisonous. He also made the light bulb.
Thomas Jefferson wrote the Declaration of Independence and had also sent the 2 great explorers Lewis and Clark to explore the Louisiana Purchase

Answer 2

Well, if you want to know...

From the moment that Jefferson was inaugurated, he began what he described as the Revolution of 1800. This was his attempt to repeal major actions that he felt the Federalists had taken to needlessly strengthen the hand of the Federal government. This included allowing the Alien and Sedition Act to lapse and the repeal of the federal whiskey tax. For all Jefferson's changes, his Presidency was more one of stability than of change.

Jefferson was a leading advocate of strict interpretation of the Constitution. Despite this fact, he took two major actions in his first term that, under a strict interpretation of the Constitution, he lacked the power to do. The first was to send forces against the Barbary Pirates. His orders to the force commander instructed him to take military action to end forced payment of ransom. The policy was successful, but Jefferson did not consult Congress before instructing this use of force.

Second, in secret negotiations, Jefferson agreed to purchase the Louisiana Territory from France. This purchase, for $15 million, doubled the size of the United States. There was, however, no provision in the constitution that provided for the purchase of land.