Model United Nations in the United States is a popular extracurricular activity for middle school, high school, and college students. The United States was where Model United Nations originated and was popularized, and is also where many of the world's most respected conferences are held. The U.S. has several regional centers of Model UN, each with its own distinct style. Traditionally, Model UN has been associated with affluent schools and communities, but in recent years, the activity has expanded to reach more students.