Abraham Lincoln (February 12, 1809–April 15, 1865), the sixteenth Presient of the United States, successfully led his country through its greatest crisis, the Civil War, only to be assassinated less than a month after the war's end. Before his election as President, Lincoln was a lawyer, a member of the United States House of Representatives, and an unsuccessful candidate for election to the Senate. As an outspoken opponent of the expansion of slavery in the United States, Lincoln won the Republican Party nomination in 1860 and was elected president later that year. During his term, he helped preserve the United States by leading the defeat of the secessionist Confederate States of America in the American Civil War. He introduced measures that resulted in the abolition of slavery, issuing his Emancipation Proclamation in 1863 and promoting the passage of the Thirteenth Amendment to the Constitution in 1865.