After his term in office, Jefferson eventually reconciled with Adams and they shared a correspondence that lasted fourteen years.
As president, Jefferson pursued the nation's shipping and trade interests against Barbary pirates and aggressive British trade policies. Starting in 1803, he promoted a western expansionist policy with the Louisiana Purchase which doubled the nation's claimed land area. To make room for settlement, Jefferson began the process of Indian tribal removal from the newly acquired territory. As a result of peace negotiations with France, his administration reduced military forces. He was re-elected in 1804, but his second term was beset with difficulties at home, including the trial of former vice president Aaron Burr. In 1807, American foreign trade was diminished when Jefferson implemented the Embargo Act in response to British threats to U.S. shipping. The same year, Jefferson signed the Act Prohibiting Importation of Slaves.
Jefferson was a plantation owner, lawyer, and politician, and mastered many disciplines including surveying, mathematics, horticulture, and mechanics. He was also an architect in the Palladian tradition. Jefferson's keen interest in religion and philosophy led to his appointment as president of the American Philosophical Society. 