If you think that Lincoln was harsh, be glad that Trump’s hero Andrew Jackson wasn’t President during the Civil War. The war would have been over in months, and traitors would have been quickly delt wiylth. Lincoln was a bumbler for 3 years of the War.
The South should have left in the 1830s, and it's looking like it was foolish for them to have joined the Union in 1789 in the first place. It was a bad deal for them right from the beginning.