Danish fort. Firing the fort's cannon, the signal was given for the start of a six-month revolt, which only ended when French troops were brought in from Martinique. Instead of submitting to captivity and slavery, more than a dozen men and women, including Breffu, one of the leaders, shot and killed themselves before the French forces reached them. Moravian Brethren built the first church at Emmaus in 1749. Cruz Bay was established in 1766, and includes The Battery. By 1804 the slave population reached a peak of 2,604. Denmark emancipated the slaves in 1848, and by 1850 many of the plantations were abandoned. By 1901 Saint John's population was 925, and the last sugar factory ceased operation in 1908. Between 1845 and 1945 the population declined by 70%. Purchase In 1917, during the First World War, the United States purchased the U.S. Virgin Islands for $25 million from the Danish government in order to establish a naval base. It was intended to prevent expansion of the German Empire into the Western Hemisphere. As part of the negotiations for this deal, the US agreed to recognize Denmark's claim to Greenland, which they had previously disputed. During the 20th century, private investors acquired properties on the island, redeveloping some plantation houses as vacation resorts, such as Laurence Rockefeller's Caneel Bay Resort. The islands became popular and tourism and related service jobs developed as a major part of the economy. Hurricane Irma In September 2017, Saint John was hit by Hurricane Irma. The category 5 storm forced roughly half of the island's 4,500 residents to evacuate and caused power outages that lasted for months. Government Since 1917, the U.S. Virgin Islands are an organized, unincorporated territory of the United States. Its residents are U.S. citizens, but they cannot vote in presidential elections. Until 1970, governors of the territory were appointed by the US president. Since that year, residents of the island have elected a territorial governor and lieutenant governor, and fifteen senators to the legislature, representing all three islands. Seven are elected from the district of Saint Croix, seven from the district of Saint Thomas and Saint John, and one senator at-large (who must be a resident of Saint John) are elected for two-year terms to the unicameral Virgin Islands Legislature. Residents of the Virgin Islands also elect a delegate to the US Congress, who has non-voting status in that body. Saint John