Abraham Lincoln served as the 16th President of the United States. Lincoln took office in 1861 and won re-election in 1864. Lincoln did not serve out his second term in office, as John Wilkes Booth assassinated him on April 14, 1865 as he watched a play at Ford's Theater.
Lincoln assumed the presidency as a Northerner and a member of the anti-slavery Republican Party, exacerbating tensions with the slaving-holding states in the South. Upon his election, seven states seceded from the United States and formed the Confederate States of America. After four more states joined the Confederacy, Lincoln supported a war effort to reunify the nation and end secession. For four years, battles raged between the Union army representing the U.S. government and the troops from the Confederacy. In 1863, halfway through the war effort, Lincoln undertook perhaps his most famous action when he issued the Emancipation Proclamation, freeing the slaves held in the Confederacy.
Lincoln first entered politics in 1834 when voters elected him to serve in the Illinois House of Representatives as a member of the Whig Party. Lincoln served in the state legislature until 1847 when he ran for and won a seat in the U.S. House of Representatives. In 1858, Lincoln ran as a member of the newly founded Republican Party against Illinois' incumbent Democratic senator, Stephen Douglas. Though he lost the election, Lincoln's race against Douglas raised his national profile and made him a viable candidate for president in 1860 election.