you can’t purchase an entirely new identity with valid paperwork.
But it only costs about a thousand dollars to purchase a new identity – or you can make one up your own self.
There are internet sites that detail ways to get it done. In most US counties, you can mail away for any birth certificate and pay the fee, and then use it to begin the process.
Or, you can print up a blank and fill it in. The internet gives you almost unlimited access to forged identity sites – you can order up an ID from almost any state on line. It isn’t valid, and won’t get you through airport security, but you can use it to open a bank account. And you can take it into a DMV in another state and probably, maybe, get a real ID issued – but those days are numbered as technology makes detection of fraudulent ID cards more available.
But starting with the BC, real or forged, yours or not yours, you can establish a whole new identity. It is illegal to steal an identity or to commit forgery, but to make one up, I am not sure. You cannot for example get a new social security number, but if you invent an identity and then use that invention to get the number.
As long as it is not for fraud, I am not sure if there is a law against that. Yet. You can for sure change your name legally, but then you keep your identity chain. It is easy to follow.
And a skilled searcher can follow you from identity to identity unless you begin the new one totally fresh, with no ties whatsoever to the old one. That means, getting a mail box in the name of the new identity before you ever use it, and never receive any mail for one where the other is. And that’s just for starts.