The U.S. military occupied Haiti between 1915 and 1934. This encouraged international interest in Vodou, with some practitioners arranging shows based on Vodou rituals to entertain holidaymakers, especially in Port au Prince. The period also saw growing rural to urban migration in Haiti, and the increasing influence of the Roman Catholic Church. 1941 saw the launch of "Operation Nettoyage" (Operation Cleanup), a process backed by the Roman Catholic Church to expunge Vodou, resulting in the destruction of many ounfos. Violent responses from Vodouists led President Élie Lescot to abandon the Operation. The Church's influence in Haiti was curtailed by François Duvalier, the President of Haiti from 1957 to 1971, who associated himself with Vodou and utilised it for his own purposes. Duvalier's administration helped Vodou rise to the role of national doctrine, calling it "the supreme factor of Haitian unity". Under his government, regional networks of oungans doubled as the country's "chefs-de-sections" (rural section chiefs). After his son, Jean-Claude Duvalier, was ousted from office in 1986, there were attacks on Vodouists perceived to have supported the Duvaliers, partly motivated by Protestant anti-Vodou campaigns. Two groups, the Zantray and Bode Nasyonal, were formed to defend the rights of Vodouizans to practice their religion. These groups held several rallies and demonstrations in Haiti.