Abraham Lincoln (February 12, 1809 - April 15, 1865) was the sixteenth President of the United States. As Commander in Chief of the United States, he led the Union during the Civil War. On April 15, he was shot in the back of the head at Ford's Theater by John Wilkes Booth. Lincoln died shortly thereafter. Andrew Johnson (December 29, 1808 - July 31, 1875) was the 17th President of the United States, and ascended to the office during his Vice-Presidency under Abraham Lincoln.