The sixteenth president of the United States, who held the Union together through civil war, issued the Emancipation Proclamation, and was assassinated five days after the Confederate surrender — and whose use of war powers, redefinition of the American founding, and management of an unwinnable political coalition established the modern American presidency.
Lincoln entered the presidency committed to not touching slavery where it existed. He left it having issued the Emancipation Proclamation, pushed through the Thirteenth Amendment abolishing slavery entirely, and redefined the American founding from a compact of liberty for property-owning men to a proposition that all men are created equal. This was not the plan. The question his career raises is how much of this transformation was forced on him by events, and how much he made happen.