How do I get my Driver's license?

I am not an american citizen yet but I want to be able to drive.I got married in July and I have an Employment Authorization Card now.I have a diver's license from Portugal. I thought i only needed my pport and my marriage certificate to do the written test but the officer told me I couln't because my pport didn't have a Visa. He said I needed a Visa but it doesnt make sense to me. How can I work if i can't drive!?!!!!