I don't believe so, if it's a union kept together at the point of a gun.
What of the American concept of freedom of association?
You have to use the perceptual lens of that time-not now. Our concept of freedom here in America is different than it was back then. There was slavery, only white men could vote, women couldn't own property (or at least it was very hard for them to), women couldn't serve in the military, we killed the indians and marched them off of their own land, etc.
None of those things (whether you agree with them or not-I'm talking about anarchism here), are a part of the current views of freedom in America-but were perfectly acceptable in many-if not all areas-of America back then.
While I personally am not sure on my thoughts about whether those who died was worth it or not, it's irrelevant, because many of those soldiers thought it was. And it happened in a time frame, and culture very different from our own.