Each state has its own requirements as to what documents are required. This is a state matter as far as what the government requests from anyone who wants to marry. There is no specific federal guideline about documents required by foreign nationals.
I am assuming you are a US citizen.
If you intend to marry, then the visitor visa is the wrong visa. You will need to petition him for a K-1 visa. Once he enters with a K-1 visa, you will have 90 days to get married. After you get married, he can file for adjustment of status.
You should retain an experienced immigration lawyer to review all the facts and advise you accordingly.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship.
Tell your boyfriend to have a look at my German webpage: http://www.wolfklaw.com/html/heirat.html
It shows the possibilities and also the problems with the "visitor visa" route. Generally you are not supposed to come as a visitor when you know that you will want to marry and stay. This is called "preconceived intent to immigrate" and could cause problems.
Otherwise, the documents he will need are his passport, birth certificate (if not in English, than a translation) and if he had been married before, then any divorce documents etc. If he has any criminal record, he would need court documents. But in that case you definitely should consult an attorney first, anyway.
Wolf W. Kaufmann
Southern California Immigration Attorney
No client-attorney relationship is being created by this posting. Please contact an attorney with questions about your case.