Abraham Lincoln freed the black slaves in USA. They went to war over this; many died. Despite not engaging in harsh verbal judgment of the southern states, Lincoln was still very willing to fight them, declare slaves free in those states and ensure his army make them free. He had an obligation to make sure the southern states came back into the union, but in doing so he was still going against the will of the southern states. In abolishing slavery, he was ensuring the economic downfall of the south. He did not want to do that, but it was an inevitable consequence if he was going to free slaves. They were locked into poverty after the slaves went free.
Slaves are still used today, but what could Lincoln have done about that? They are used all over the world.
If he were not an abolitionist, he would not have abolished slavery. It is typical in politics for leaders to be criticized by both sides if they are moderate and sensible, and Abraham Lincoln was moderate and sensible. He went about freeing slaves in a clever and practical way, and he did it while knowing that white Americans were going to suffer, and suffer for a long time. Let us consider that whites were and still are a majority in US. For someone who did sympathize with whites in the south, he chose the African American slave over them. He has earned the right to be called an abolitionist.