Final answer:
The US added three new amendments to the Constitution after the Civil War - the 13th, 14th, and 15th amendments. The 13th amendment abolished slavery, the 14th amendment protected citizens' rights, and the 15th amendment protected voting rights.
Step-by-step explanation:
The 13th amendment abolished the practice of slavery in the United States. The 14th amendment protected the rights of citizens in the United States and considered Africans as a "whole" person. The 15th amendment protected the rights of citizens to vote and stated that voting rights cannot be denied based on race, color, or previous status of slavery.
Learn more about Civil War Amendments