Although Medals of Honor can be presented only to members of the U.S. armed forces it is not required to be a U.S. citizen. Since the American Civil War hundreds of people born outside the United States have received the medal. The most recent of these recipients being Leslie H. Sabo, Jr.. He received his medal in May 2012 for actions performed during the Vietnam War. The large number of foreign-born recipients during the 19th and early 20th centuries was likely due to immigration waves from Europe.