Thomas Jefferson won in 1804, running with George Clinton as his vice president against John Adams due to growing distrust of big government and a desire to end the tribute to the Barbary states. Thomas Jefferson ends the tribute immediately and the Barbary states gives permission to the pirates to attack American vessels. This starts the Barbary War.
1st Barbary War
Thomas Jefferson sends in the now large navy to fight against the Barbary pirates and the states supporting them. This war would last from 1805-1809 ending in an American victory. However, Algiers would take advantage of the War of 1812 and begin to attack American ships again.
With the 1st Barbary War almost over Thomas Jefferson easily won reelection in 1808. In 1811 the First National Bank expired. In 1812 his vice president, George Clinton died of a heart attack and he was replaced with James Madison.
War of 1812
Thomas Jefferson had had enough of British impressing American ships and their sailors into service, and so had Canada invaded. However, this was repulsed. Thomas Jefferson is reelected again by a smaller margin. The Federalist Party is mostly opposed to the war and in 1814 the Hartford Convention is held. However, unlike in OTL the president never calls for national conscription, and in fact denounces calls for it from Congressmen. A treaty is signed in 1814 keeping the territory almost exactly the same except for Carleton Island going to the United States.
2nd National Bank
Thomas Jefferson decides to bring back the national bank since it had proved difficult to fight the war without it.
2nd Barbary War
In 1815 Thomas Jefferson directs the navy against Algiers which had permitted piracy against American vessels for years taking advantage of the War of 1812. The war ends the same year with a treaty ending piracy.
With the Federalist Party seen as treasonous for its support of Britain and the Hartford Convention Thomas Jefferson easily wins the election. The Federalist Party disbands soon after.
In Jefferson's 4th term Jefferson supports statehood for Missouri. However, he views the Missouri Compromise as unconstitutionally infringing on state's rights. Jefferson also fears the Missouri Compromise would divide the Union in two. Jefferson calls the admision of Missouri and Maine but without prohibiting slavery in any US territory. This compromise is eventually accepted.
President Jefferson got his 5th term in office effectively unopposed. The United States would annex Florida from Spain in 1821 and after that he began recognizing the several Latin American countries that had just achieved independence.
Thomas Jefferson proclaimed the Jefferson Doctrine which was a warning to European powers from meddling in the Western Hemisphere.
Just 2 years into his 6th term Thomas Jefferson died. His vice president James Madison became president.