If you are a US citizen you have a couple of options, depending on how soon he wants to get to the US. You could apply for a fiancee visa for him, and this will probably take 4-6 months. You will need to get married within 90 days of him entering the US on the fiancee visa.
You could also marry him overseas, and then go through the immigrant visa (green card) process through a US consulate. This is likely to take about twice as long as a fiancee visa.