He did so because he wanted revenge on France and England for winning the first war. He was a young soldier in the WWI and felt that Germany was shamed after the war. So he started the second to gain respect back and to prove that their country was also a great superpower. He believed in racial purification and wanted to take over Europe and remodel it the way he wanted.
The Congressional and Presidential Reconstruction Plans had differences as regards the intensity of amnisty and leniency they managed. President Lincoln believed that he had the power and the obligation to carry on the Reconstruction. However, the Republican Members of the Congress did not agree. They said that it was the Congress the one with the power to reconstruct the south.
