F-1 Overstay

Ohio, I came to US 9 years ago and finished school. Afterwards, I was not able to find a job which would have allowed me to switch to H-1. I have been out of status for 4+ years. My USC girlfriend wants us to get married. I want to find out what are the implications as far as the necessity to leave the country or if my status can be adjusted without having to leave. I was given a SSN but wasn't allowed to work but did engage in employment. Thanks

If you leave the country you will become subject to a period of ineligibility from reentry. As you entered the U.S. legally you should be eligible to adjust your status on the basis of marriage, but you don't want to leave the country before that happens.