Slavery:
At the Constitutional Convention, the delegates were concerned with the survival of the young nation. Many delegates called for strong protections for slavery, while many others hated the idea of putting into the Constitution the idea that there could be property in people. With the goal of forming a Union, they reached a compromise. Slave states would count 3/5ths of their slave populations towards their state populations to calculate taxation and representation in Congress. This is known as the 3/5 Compromise. Additionally, Congress could not outlaw the international slave trade until 1808. The debate over the federal government's power to regulate slavery continued through the Civil War.
James Buchanan, Abraham Lincoln, and Andrew Johnson, who served as President of the United States in the years immediately before, during, and after the Civil War, each had different approaches to the constitutional powers of the President, if any, to interfere with the spread of slavery.
At the end of the Civil War, the Reconstruction Amendments, the 13th Amendment, 14th Amendment, and 15th Amendment, were added to the US Constitution. The three amendments abolished slavery, granted citizenship regardless of race, and allowed Black men the right to vote.
