FOIA REQUEST??? Anyone know about this?

When I called a local law firm to consult about my situation, I was told to get an FOIA request.. to figure out what my status is. I know i'm un-documented, but I guess I still need to do it?
I've been told that my situation can not be fixed unless I show proof of me entering the U.S. Is this true? I've heard of lots of illegal people getting married to US citizens (for the wrong reasons) and immediately changing there status.. is this possible??
HELP!

It is true in some respects,but I would like to highlight I highly suggest not to go to that particular law firm if they are suggesting you do an FOIA by yourself.

Only those legally inspected can have their status adjusted through US citizen immediate relatives..... even with unlawful presence.Those that came over the border illegally would have to return to their country of origin for any adjustment process unless covered under 245i.