Pull Citizen Records to Website

I can't seem to find any real way of pulling public records to a website.

I'd like to be able to confirm visitors are US citizens without having to worry about the anxiety relating to Social Security numbers and private information, etc.

So, if I were to create a website, and I wanted to accomplish this, what code/tools would I use to do so? Does anyone know of a way to code against X government website API or something to accomplish this, or am I looking at collecting a database of every citizen in America in public record... or what?

Thanks.