Of the seven Presidents who have died in office, Lincoln's death was the most consequential for America. Lincoln was succeeded in office by his Vice-President, Andrew Johnson, a shallow, resentful drunk who hated Southern aristocrats and blacks (freed and slave) equally and whose only gift was for alienating his fellow politicians.
In 2012 THC wrote:
I'd like to think that Reconstruction would have achieved more for the former slaves if Abraham Lincoln had lived rather than having Andrew Johnson, who was actively hostile to all African Americans, in charge from 1865 to 1868. But even Lincoln would have faced a huge challenge since Northern public opinion would not have accepted full equality. Could he have successfully maneuvered to create a future where the post-war Constitutional amendments and the Civil Rights Act of 1866 did not become dead letters and at the same time not trigger a second rebellion or electoral defeat even in the North for the Republicans? If so, it might have been an even greater achievement than preserving the Union and guiding us through the Civil War.The great tragedy for America was that Lincoln never had the chance.