Slavery throughout the United States was permanently abolished by the a
ratification of the Constitution of the United States
b
approval of the Republican Party platform of 1860
c
issuance of the Emancipation Proclamation
d
adoption of the 13th amendment to the Constitution

D.  Adoption of the 13th amendment to the Constitution.

Explanation:

The 13th Amendment to the United States Constitution permanently abolished slavery in the United States.

A lot of people believe that the Emancipation Proclamation abolished slavery in the United States, this is false. The Emancipation Proclamation was issued by President Abraham Lincoln, whose main goal was to keep the country together and shorten the war. The proclamation freed all slaves only in the rebellious states or states that were part of the Confederacy. The border states that were essentially part of the Union but had slaves did not have to get rid of their slaves. The Emancipation Proclamation was seen as a tactic to shorten the war by making the rebellious states less powerful. If they did not have slaves to help on plantations, they would lose money, causing them to not be able to buy weapons or supplies.

The 13th Amendment was adopted into the United States Constitution on December 6, 1865 . It abolished slavery and involuntary servitude in the United States unless it is for punishment for a crime.