The Exotic American Island No One Knows About Photo credit: CC license by Field, Photographer 11. Guam was once owned by Spain When the Spanish-American war concluded, Guam was ceded to the United States by Spain. This is a big reason for all of the Spanish and Catholic influence on the island. After the island was ceded, Guam and its people were granted protection by the U.S. Constitution, the use of the American dollar, and full American citizenship. Prev11 of 17Next From Around The Web Facebook Comments comments