The American Mafia, also known as La Cosa Nostra, is a criminal organization that originated in the United States in the late 19th century. It is primarily composed of Italian-American members and is known for its involvement in various illegal activities, including extortion, racketeering, and organized crime. The Mafia operates through a hierarchical structure, with a boss at the top, followed by underbosses, capos, and soldiers. Throughout the 20th century, the American Mafia gained significant power and influence, particularly during the Prohibition era when illegal alcohol trade flourished. Notable figures include Al Capone and Lucky Luciano, who played key roles in shaping the organization. Law enforcement efforts have led to numerous arrests and convictions, but the Mafia continues to exist in various forms today.