Florida is an at-will state, meaning you or your employer may terminate the employment relationship at any time for any reason.
While this has benefits to the employee, in your case you really have no recourse unless you are/were protected by a contract or labor agreement (union).
The good news is you were exonerated, so you won't have a conviction on your record. Plus, since you were terminated, you MAY qualify for unemployment to help get you through to your next job. Check with the Florida unemployment office to confirm if you qualify in your case.
Good luck!
The law is that you can be fired for any reason whatsoever as long as it isn't related to your age/race/gender/religion/etc. You can absolutely be fired for a felony charge, and you can be fired for no reason whatsoever.
Your employer doesn't have to give you the opportunity to prove yourself innocent. If they choose to fire you for something that is unsubstantiated then they have to pay your unemployment, which is happening here. Likewise if you suspect that your employer is doing something you don't approve of you are free to quit at any time without them having to prove anything to you. It's a two-way street.
Don't confuse being found not guilty with being exonerated. The only thing a not guilty verdict means is that the prosecution was unable to prove that you were guilty in court. The fact that you were charged with felony fraud and there was enough evidence for the case to go to trial means that something happened, even if it couldn't be proven to be criminal. Cases don't go all the way to trial unless there's some kind of substance to the charges. Depending on the kind of job you have that could be enough for an employer to decide that you're too risky to have around.
You can hire an attorney to attempt to clear the charges from your record if this is possible in your jurisdiction. This will not be cheap and it will not be easy though. You know the details of your case better than anybody here so you have to decide if it's worth it to try.