The Hawaiian Islands were economically important to the U.S. American merchants stopped there on their way to China and East India. Yankee missionaries founded Christian churches and schools on the islands. American-owned sugar plantations in Hawaii accounted for 3/4 of the islands' wealth, and they were able to sell their sugar to America duty-free. The McKinley Tariff of 1890 provoked a crisis by eliminating the duty-free status of Hawaiian sugar. American planters in Hawaii called for the U.S. to annex the islands so they wouldn't have to pay the duty. When Queen Liliuokalani came to power in 1891, she wanted to return Hawaii to Hawaiian's control, by removing the property-owning qualifications for voting. This angered white plantation owners. With Ambassador Stephens, they organized a revolution. With the help of the marines, they overthrew the queen and set up a government headed by Sanford. B. Dole. President Cleveland wanted the queen restored to her throne, but Dole refused to do so, so Cleveland formally recognized the Republic of Hawaii. In 1897, William McKinley succeeded Cleveland as president of the U.S. He favored annexation. On August 12, 1898, Congress Proclaimed Hawaii an American territory. In 1959, it became the 50th state of the U.S. Americans believed they needed a canal across Central America to reduce travel time for commercial and military ships by providing a shortcut between the Atlantic and Pacific oceans. In the Hay-Pauncefote Treaty of 1901, Britain gave the U.S. exclusive rights to build and control a canal through Central America. In 1903, the U.S. decided to use the Panama route and agreed to buy the French company's route (which failed in the late 1800's) for $40 million. The U.S. had to get permission to build the canal from Colombia, who ruled Panama. Initially, talks broke down. Bunau-Varilla, a French agent for the canal, helped organize a Panamanian rebellion against Colombia. On November 3, 1903 Panama declared its independence. 15 days later, Panama and the U.S. signed a treaty in which the U.S. agreed to pay $10 million plus an annual rent of $250,000 for an area of land across Panama. The canal reflected America's new role as a world power. Construction of the canal is one of the world's greatest engineering feats. 5,600 workers on the canal died from accidents or disease. They had to deal with soft volcanic soil which was difficult to remove, and had to deal with yellow fever and malaria. The canal cost $380 million and opened on August 15, 1914. Mexico had been ruled by a military dictator, Porfirio Diaz who was a friend of the U.S. In 1911, Mexican peasants and workers led by Francisco Madero overthrew Diaz. After 2 years, Madero was unable to satisfy the conflicting demands of landowners, peasants, workers and the urban middleclass. General Victoriano Huerta took over the Mexican government and murdered Madero. President Wilson, sticking to the "missionary diplomacy" refused to recognize the government that Huerta formed, calling it a "government of butchers." Wilson waited for an opportunity to intervene in Mexico. After a small group of American sailors was arrested, Wilson ordered U.S. Marines to occupy Veracruz, an important Mexican port. 18 Americans and 200 + Mexicans died during the invasion. The incident brought the U.S. and Mexico close to war. The Huerta regime soon collapsed and Venustiano Carranza, a nationalist leader, became president in 1915. Wilson withdrew U.S. troops and formally recognized the Carranza government. U.S. intervention in Mexican affairs provided a clear model of American imperialist attitudes in the early 20th century. Americans believed in the superiority of free-enterprise democracy and they attempted to extend the reach of this economic and political system, even through armed intervention. Mexican rebel who opposed Carranza's provisional government. He was a fierce nationalist. When Wilson recognized Carranza's government, Villa threatened reprisals against the U.S. In 1916, Villa's men removed American engineers from a train and shot them. His followers also raided Columbus, New Mexico and killed 17 Americans. President Wilson sent Brigadier General John J. Pershing and 15,000 soldiers into Mexico to capture Villa dead or alive. After a year, Wilson called out 150,000 National Guardsmen and stationed them along the Mexican border. Carranza's government and Mexicans grew angry over the U.S. occupation of their land. In June, 1916, U.S. troops clashed with Carranza's army, resulting in deaths of both sides. Carranza demanded the withdrawal of U.S. troops, but Wilson refused. War seemed imminent, but both sides backed down. In February 1917, Wilson ordered Pershing to return home.