After termination, I received incorrect final check amount

What is the name of your state (only U.S. law)? Illinois

1. There was no employee handbook when I got hired and he never asked for my social security number or eligibility to work. After working at his office for 3 months, he asked for my social security card out of nowhere. As an employer, isn't he responsible to check future employee's work eligibility and give an employee handbook? When I file a law suit, can he use the fact that I didn't give him information about work eligibility when he never asked for me before he hired me? Or can I use the fact against him that he never gave me an employee handbook or checked my work eligibility?

2. On the offer letter he e-mailed me, he agreed to pay me a certain amount of bonus at the end of the year and he terminated a month before I could receive my big bonus. After termination, my ex-boss sent me incorrect final check amount with no pro-rated bonus, exam reimbursement fees or vacation days.

4. I was eligible to work in the US when he hired me but found out that my employment card was expired after 5 months of working there and had to re-apply for a new employment card. Therefore, for 2 months, I worked without valid employment card. If I forgot to renew my employment card, can my employer use that against me even if I had an eligible employment card at the time when I got hired? If I file a law suit about final check amount, can he use that against me?

Now he says that since my termination was based on causes, he can't give me any bonus and he is claiming that I used my vacation days, which are not true. I have enough evidence to prove that his causes are based on what he has heard from other co-workers. I am very disappointed with his integrity and please advise what I need to do. Thank you..

1. There is no law that requires the employer even HAVE an employee handbook, much less that you be given a copy. Your work eligibility should have been verified no later than your 3rd day of work. However, any disciplinary action or fine would be imposed by the USIS (or whatever it's called these days); you have no standing to sue for this issue since the violation was not committed against YOU.

2. The great majority of offer letters are not bona fide contracts. Only a local attorney versed in contract/employment law could advise you as to whether yours was an exception.

3. What happened to question 3?

4. See #2.

BTW, you can be fired for any reason not specifically prohibited by law. There is no law that says you can't be fired because of what he hears from co-workers. There is also no law that says you can't be fired for something you didn't do.

He may be lacking in integrity but he does not appear to be violating any laws.