Abraham Lincoln, the 16th President of the United States, served from March 1861 until his assassination. He led the country through a great constitutional, military and moral crisis-the American Civil War-preserving the Union while ending slavery and promoting economic and financial modernization. Reared in a poor family on the western frontier, Lincoln was mostly self-educated. He became a country lawyer, an Illinois state legislator, and a one-term member of the United States House of Representatives but failed in two attempts at a seat in the United States Senate. He was an affectionate, though often absent, husband and father of four children.