Chief island (pop., 1990: 48,000), U.S. Virgin Islands .
Located east of Puerto Rico, it covers an area of 32 sq mi (83 sq km). The capital, Charlotte Amalie , has a well-sheltered harbour. Sighted in 1493 by Christopher Columbus , St. Thomas was colonized first by the Dutch (1657) and then by the Danish (1666). After 1673, when slavery was introduced, the island became one of the chief Caribbean sugar producers and a major slaving centre. Falling sugar prices after 1820 and the abolition of slavery in 1848 led to a decrease in profits. The U.S. bought St. Thomas for use as a naval base in 1917. The chief industry is tourism.