[ZTAngel]

I would assume that many background checks could discover your job history.
They do background checks through your social security number which is attached to your tax records which are attached to your employment records. I had always heard that even if you leave off a job on your resume or application that some company's background checks can find out about it. My friend's company did an extensive background check on her. They looked into her school records and job history. Someone from the company called her and asked why she hadn't included A&F on her job history and she just said, "I didn't think my experience there was relevant to the job requirements here and I was only at Abercrombie for 2 months." I'm assuming that they found that through her social security number but maybe someone who knew her worked for the company and mentioned she worked at A&F. I dunno. I don't think the background checks can see if you were fired, though.

ETA:
I just wanted to mention that Credit Reports are becoming a big thing for companies to check up on.