Why can't you just tell us what documents you possess that prove you are a citizen?
I have a passport, but it cost me over $120 to get it. I have a birth certificate and a thing with my baby footprints on it, but it lacks a photo ID and of course, my signature. It seems I was born illiterate.
The solution to all this would be for the federal government to issue a national ID card, what the French call a Carnet, that has a photo and a signature on it. This was proposed back when Jimmy Carter was president, and the republicans opposed it. No one disputed voter ID's at that time.