Originally a Spanish colony, it was acquired by the United States during the Spanish-American War. By then, it had a distinctive Hispanic culture and language that combined Amerindian, African, and European elements
Puerto Ricans have been citizens of the United States since 1917, and can move freely between the island and the mainland. According to the 2010 Census, the number of Puerto Ricans living in the United States outside of Puerto Rico far exceeds those living in Puerto Rico.
There are various less politically correct views. See the “External links” section.