This is one of those "sophomore" things.

Where a very basic answer, could be yes. The more complex and nuanced answer is no. But at the end of the day if you asked an expert they would say, in a nutshell, yeah.

See also, slavery in the civil War. Was the war fought to end slavery? yes.

If you want to be pedantic it didn't start off as a war of liberation and there's quite a bit to say about treatment of black people in the North, and the slave states that were still part of the Union during the war.

But the end of the day if you had to answer with yes or no, the answer is "yea"

should have just said to the kid "eh more or less"