American commander demanded Mexico for an apology, but Mexico refused. President Wilson saw this refusal as an opportunity to overthrow Huerta. Shortly after Congress authorized the use of force, he learned that a German ship was unloading weapons at the Mexican port of Veracruz. He immediately ordered American warships there, where marines forcibly seized the city. Although Wilson expected the Mexicans to accept his action, anti-American riots broke out. Wilson then accepted international mediation to settle the dispute. Venustiano Carranza, whose forces had acquired arms from the U.S., became Mexico's president. Mexican forces opposed to Carranza were not appeased, and they conducted raids into the U.S., hoping to force Wilson to intervene. In March 1916, Pancho Villa and a group of guerillas burned the town of Columbus, New Mexico, killing 17 people. Wilson responded by sending about 5,800 troops under General John J. Pershing across the border to find and capture Villa. The expedition dragged on with not success. Wilson's growing concern over the war raging in Europe finally caused him to recall Perishing's troops in 1917. Wilson's Mexican policy damaged U.S. foreign relations. The British ridiculed the president's attempt to "shoot" the Mexicans into self-government. Latin Americans regarded his "moral imperialism" as no improvement over Roosevelt's "big stick" diplomacy. Wilson followed Roosevelt's example in the Caribbean, negotiating in 1914 exclusive rights for naval bases and a canal with Nicaragua. In 1915 he sent marines into Haiti to put down a rebellion. The marines remained there until 1934. In 1916 he sent troops into the Dominican Republic to preserve order and set up a government he hoped would be more stable and democratic than the current regime. In 1899, Emilio Aguinaldo ordered his troops to attack the American soldiers who had been sent to the Philippines. The U.S. met resistance in the Philippines. This conflict lasted until almost 1902. To fight the Filipino guerrillas, the U.S. military established reconcentration camps to separate Filipino guerrillas from civilians. While American troops fought these guerrillas, Reforms introduced by William Howard Taft such as education, transportation, and health care slowly helped to reduce Filipino hostility. In March 1901, American troops captured Emilio Aguinaldo. On July 4, 1902, the U.S. declared the war over. Gradually, the Filipinos gained more control over their government. By the mid 1930s, they elected their own Congress and president. In 1946 they gained full independence from the U.S. Porfirio Diaz was dictator of Mexico for more than 30 years. During his reign, Mexico became much more industrialized, but foreign investors owned and financed the new railroads and factories that were built. Most citizens remained poor and landless. In 1910, discontentment erupted into revolution. Francisco Madero, a reformer who seemed to support democracy, constitutional government, and land reform, led the revolution. However, he proved to be an unskilled administrator. Consecutive forces plotted against him because they worried about his plans for land reform. In 1913, general Victoriano Huerta seized power, and Madero was murdered. Huerta's brutality disgusted Wilson, who refused to recognize the new government. Instead, he announced a new policy. To win U.S. recognition, groups that seized power in Latin America would have to establish a government based on law, not force. Wilson believed that, without U.S. support, Huerta would soon be overthrown. Meanwhile, Wilson ordered navy to intercept arms shipments to Huerta's government and also permitted Americans to arm Huerta's opponents.