Haiti's first century of independence was characterized by political instability, ostracism by the international community and the payment of a crippling debt to France. Political volatility and foreign economic influence in the country prompted the U.S. to occupy the country from 1915 to 1934. Following a series of short-lived presidencies, François 'Papa Doc' Duvalier took power in 1956, ushering in a long period of autocratic rule that was continued by his son Jean-Claude 'Baby Doc' Duvalier that lasted until 1986; the period was characterized by state-sanctioned violence against the opposition and civilians, corruption, and economic stagnation. After 1986, Haiti began attempting to establish a more democratic political system.