The occupation improved some of Haiti's infrastructure and centralized power in Port-au-Prince. 1700 km of roads were made usable, 189 bridges were built, many irrigation canals were rehabilitated, hospitals, schools, and public buildings were constructed, and drinking water was brought to the main cities. Port-au-Prince became the first Caribbean city to have a phone service with automatic dialling. Agricultural education was organized, with a central school of agriculture and 69 farms in the country. However, many infrastructure projects were built using the corvée system that allowed the government/occupying forces to take people from their homes and farms, at gunpoint if necessary, to build roads, bridges etc. by force, a process that was deeply resented by ordinary Haitians. Sisal was also introduced to Haiti, and sugarcane and cotton became significant exports, boosting prosperity. Haitian traditionalists, based in rural areas, were highly resistant to U.S.-backed changes, while the urban elites, typically mixed-race, welcomed the growing economy, but wanted more political control. Together they helped secure an end to the occupation in 1934, under the Presidency of Sténio Vincent (1930–41). The debts were still outstanding, though less due to increased prosperity, and the U.S. financial advisor-general receiver handled the budget until 1941.