Before he was killed he was making many plans to bring the union together but since he was killed by a southern John Wilkes booth, people were enraged and this caused a little bit of a rage making it harder for the north to bring in the south into the union again( not 100% sure I am learning about this at the moment and reading a book about it , hope it helped
Simply put, Lincoln believed that the Confederacy should be peacefully brought back into the Union. Lincoln'ssuccessor, Andrew Johnson, believed the exact opposite. Johnson believed that the South should be punished for what they did and, as a result, dealt much more harshly with the South then Lincoln intended. It then, of course, did not help matters that the man who shot Lincoln, John Wilkes Booth, was a famous Southern actor. Someone that the South idolized became the enemy of a nation. Johnson, who, as I said, wanted to punish the South. Therefore, he used Booth as an excuse to go after the former Confederacy with the full force of his administration.
