If Lincoln had lived longer, would he have done even more useful things for the country or not?

He would have kept Reconstruction on track.

No way to tell. Speculative history post-mortem is a fool’s game.

^agreed

He would be assassinated just like any person capable of real change.

Jesus, MLK, Kennedy, Fred Hampton etc.
Lincoln pissed off a lot of poor and rich white people.

Adding black people to the pool of humanity means less jobs for poor white people.

He was gonna end up being killed either way. Poor white men throw hissy fits when things don’t go their way.

Honestly, he probably would have lived long enough to be the villain. The only reason he isn’t blamed for the destruction of the south, the failure of reconstruction and the ensuing Jim Crow era, was because he was killed. He did start the deadliest war in American history, after all. Sure, he had his reasons, but politicians who live rarely get to ride the happy horse into the sunset. The country would need to move past the Lincoln era, and might have been able to more honestly address the past without lionizing yet another politician. To what end? I have no idea.