Quick answer (verified 2026-07-08 by CivicFlare):
Official USCIS answer to "What U.S. war ended slavery?": The Civil War. Learn historical context and practice online with CivicFlare.
OFFICIAL USCIS ACCEPTED ANSWER(S)
The U.S. Civil War was fought between the Northern states (Union) and the Southern states (Confederacy).
The USCIS includes questions about American-history / 1800s to ensure new citizens understand the foundational structures, laws, and history of the United States. Knowing the correct answer demonstrates your attachment to the principles of the U.S. Constitution.
When the USCIS officer asks you, "What U.S. war ended slavery?", speak clearly and confidently. You do not need to give every possible answer if more than one is accepted — stating just one of the official answers (such as "The Civil War") is completely sufficient to earn full credit.
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