Answer :

Lincoln was very careful in his speeches regarding slavery not to antagonize the South. He made it clear that he didn't want to end slavery where it existed, only stop it from spreading. 
millermoldwarp

Correct answer:

He commended slavery and affirm the idea of African-Americans natural rights

Lincoln's approach to slavery was fundamentally conservative, which meant he did not want to end the slavery where he existed but only wanted to prevent it from spreading.