Married but no legal status........?

My husband entered the US on a 90 day holiday visa from England. I met him after he arrived here in the states. He and I spoke to an immigration attorney "before" we got married and he advised us to just let the visa run out, and get married when we wanted to. We have been married for 4 years and have never gone back to start permanent residency proceedings. Does anyone know if after you have been married for a period of time, do they automatically get legal status? I know that things have changed alot since 9/11. Any advice will be greatly appreciated.