Which amendment to the Constitution ended slavery in the United States?

a. Twenty-third Amendment

b. Fifteenth Amendment

c. Seventh Amendment

d. Thirteenth Amendment

The answer is the Thirteenth Amendment. This abolished slavery and involuntary servitude. Earlier President Lincoln issued the Emancipation Proclamation that declared the slaves free. This was made possible through a string of victories that supported this amendment and victory of the Union led to the abolition of slavery in the entire country.