When did Puerto Rico officially become a U.S. commonwealth?
Puerto Rico was a Spanish colony until the Spanish-American War in 1898. Following the signing of the Treaty of Paris, the island - along with Cuba, the Philippines and Guam - became U.S. territories. However, it wasn't until 1917 that Puerto Ricans received citizenship, and in 1952, Congress approved the island's local constitution, which made it a "commonwealth". To this day, the island's political status remains under debate, with some calling for statehood, others calling for independence and the rest supporting the status quo. Source: Smithsonian Magazine.