This is why you organise

Unless your in a state that doesn't require a reason to terminate. In those states as long as the "reported" reason is not one of the very few illegal ones they can certainly get rid of you. It then puts the entire onus on you to prove they fired you illegally. And just so you know the reason can be as simple as "failure to conform to company environment". That's a great generic reason and there's almost nothing you can say or do to prove that that's not the reason.