Legal Question in Immigration Law in New Jersey

Marrying him should not be an issue. Obtaining permanent residence for him through marriage to a US citizen (which I assume would be you) may be the more involved issue, depending upon how he entered the country.

You may find information one option here if he lawfully with a valid visa and merely overstayed:

http://www.smartimmigrationlawyer.com/adjustment-of-status/adjustment-of-status-requirements/

I agree. The marriage itself might not be the issue, but you should speak to an attorney about whether you can obtain permanent residence for him through marriage. I would be pleased to discuss this issue with you in person. For an appointment, please call my office at 609-927-9227. My rates are very reasonable and payment plans may be available. I would be pleased to help you.