[Non-Sequitur]

On the contrary. I think that it is Merriam-Webster who is in error. My Websters New Collegate doesn't show confederate as a proper noun, although for some reason they have an entry for something called 'Confederate Memorial Day' whatever that is. And since the confederate states was not a legal entity then it shouldn't be considered a proper noun. It's like the rustbucket states of america.

[rustbucket]

It's like the rustbucket states of america.

I promise my South will never secede.

Even McPherson capitalizes "Confederate".