As a territory of the United States, Puerto Rico uses the United States dollar as its official currency. Being a former colony of Spain, the Puerto Rican peso and other Spanish currencies had served the monetary needs of Puerto Rico.
Following Spain's ceding of Puerto Rico to the United States in 1898 after the Spanish-American War, the transitional period from 1898 to 1913 saw the introduction of the Puerto Rican dollar, and it was freely exchanged with the American dollar. By 1913, the island had become fully integrated into the United States monetary system, and the United States dollar became the sole official currency. However, with the vast Spanish history and influence on the island, many Puerto Ricans still colloquially refer to the dollar as the peso.