The U.S. occupied Haiti from 1915 to 1934. U.S.-based banks had lent money to Haiti and the banks requested U.S. government intervention. In an example of "gunboat diplomacy," the U.S. sent its navy to intimidate to get its way. Eventually, in 1917, the U.S. installed a new government and dictated the terms of a new Haitian constitution of 1917 that instituted changes that included an end to the prior ban on land ownership by non-Haitians. The Cacos (military group) were originally armed militias of formerly enslaved persons who rebelled and took control of mountainous areas following the Haitian Revolution in 1804. Such groups fought a guerrilla war against the U.S. occupation in what were known as the "Caco Wars."