The presidency of Thomas Jefferson began on March 4, 1801, when he was inaugurated as the third President of the United States, and ended on March 4, 1809. Jefferson assumed the office after defeating incumbent President John Adams in the 1800 presidential election. Upon taking office, he repealed the remaining provisions of the Alien and Sedition Acts and pardoned all ten individuals who had been prosecuted under the acts. He also began dismantling Hamilton's fiscal system with help from Secretary of the Treasury Gallatin.