Abraham Lincoln was the 16th president of the United States, serving from 1861 until his assassination in 1865. Some key facts about Lincoln include that he helped preserve the Union during the Civil War, issued the Emancipation Proclamation to free slaves, and delivered the iconic Gettysburg Address. Lincoln also promoted the passage of the 13th Amendment to abolish slavery. He was assassinated by John Wilkes Booth at Ford's Theater in Washington D.C.