OP, as someone who once also assumed the truth of the conventional wisdom of the greatness of Lincoln, please realize you have only been told the "winner's" side of the story.

As others have pointed out, Lincoln is arguably the WORST president in that he forever undermined state's rights, fundamentally changing the relationship between the federal and state government that was so carefully defined by the Founders [To be fair, the Founders fucked up by never make it clear if state's could secede, but Lincoln definitely did not have to go to war over the issue.]

Personally, I don't think he was that bad, but certainly there are a lot of myths, like he was a crusader to end slavery. Completely not true. He never had any intention to end slavery, and even when he did pass the Emancipation Proclamation, it only effected a subset of Southern areas under Confederate control - it did not free all Southern slaves and it not free Northern slaves. Any objective analysis makes it pretty clear it was a strategic play to make life harder on the Southern enemy.

Anyway, before you mindlessly repeat that Lincoln was the greatest, do some research. And remember that the people feeding you that conventional wisdom have shown no interest in the protection of your liberty.

They have agenda, and declaring Lincoln the greatest is part of that agenda.