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Most offers in this country are "at will" and can legally be ended at any time, with or without cause. So, contractually, unless your agreement stated that you could only be terminated for cause, you'd have no cause of action.
Now, that is just contractually. There is a different type of legal claim based not on contract law, but on the law of equity. It is called a "promissory estoppel" claim. The idea is that if you are made a promise that you reasonably relied on, to your detriment, you can sue for the damages from that reasonable reliance.
Here, you have the promise of employment which you reasonably relied on and, to your detriment, moved your entire family here. That would at least form the framework for the promissory estoppel claim. Different states are more or less favoring of this sort of claim, so you'd have to approach a local employment law attorney in your area to discern whether or not your courts will accept such a claim. Further, this is the sort of claim that some attorneys don't like to bring, preferring to stick to simply contract claims.
Still, there is a legally viable form of claim on your facts.
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