What were Lincoln's views on slavery?

Abraham Lincoln did believe that slavery was morally wrong, but there was one big problem: It was sanctioned by the highest law in the land, the Constitution. The nation's founding fathers, who also struggled with how to address slavery, did not explicitly write the word "slavery" in the Constitution, but they did include key clauses protecting the institution, including a fugitive slave clause and the three-fifths clause, which allowed Southern states to count slaves for the purposes of representation in the federal government.