Are there no laws in the US protecting employees from this kind of scenario? Something like Unfair Dismissal in the UK. As others have said, the first employee

Are there no laws in the US protecting employees from this kind of scenario? Something like Unfair Dismissal in the UK. As others have said, the first employees took the risk of working for a startup, any-one who joined later can't possibly deserve more because they "contributed more" because the company wouldn't exist without the original employees.