Discovered and claimed for Spain in 1499, Aruba was acquired by the Dutch in 1636. Three main industries have since dominated the island's economy: gold mining, oil refining, and tourism. A 19th-century gold rush was followed by prosperity brought on by the opening of an oil refinery in 1924. The last decades of the 20th century saw a boom in the tourism industry. Aruba seceded from the Netherlands Antilles in 1986 and became a separate, semi-autonomous member of the Kingdom of the Netherlands. Movement toward full independence was halted at Aruba's request in 1990.