Abraham Lincoln (1865)

John Wilkes Booth's assassination of Abraham Lincoln on 14 April 1865 — five days after Lee's surrender at Appomattox — removed the one political leader with the power and will to implement a moderate Reconstruction of the South. Lincoln's successor Andrew Johnson blocked civil rights legislation, enabling the Jim Crow system of legal racial segregation that endured for 100 years and shaped American race relations to the present day.