Answer:
At the time of the American Civil War, there were actually
15 states that allowed slavery in the United States. They
were:
1. Alabama
2. Arkansas
3. Florida
4. Georgia
5. Kentucky
6. Louisiana
7. Mississippi
8. Missouri
9. North Carolina
10. South Carolina
11. Tennessee
12. Texas
13. Virginia
14. Maryland (although it did not secede from the Union)
15. Delaware (also remained part of the Union)
Step-by-step explanation:
It's important to note that slavery was abolished by the
13th Amendment to the U.S. Constitution in 1865, which
put an end to legal slavery in all states and territories of
the United States.