Widely regarded as the greatest professional wrestler of all time and the best American performer of the 1980s, Flair had a career that spanned 40 years. He is noted for his tenures with the National Wrestling Alliance (NWA), World Championship Wrestling (WCW), the World Wrestling Federation (WWF, later WWE) and Total Nonstop Action Wrestling (TNA). Since the mid-1970s, he has used the moniker "The Nature Boy".