Only one year after Spain granted Puerto Rico self-rule, American troops raise the U.S. flag over the Caribbean nation, formalizing U.S. authority over the island’s one million inhabitants.
In July 1898, near the end of the Spanish-American War, U.S. forces launched an invasion of Puerto Rico, the 108-mile-long, 40-mile-wide island that was one of Spain’s two principal possessions in the Caribbean. With little resistance and only seven American deaths, U.S. troops were able to secure the island by mid August. After the signing of an armistice with Spain, the island was turned over to the U.S forces on October 18. U.S. General John R. Brooke became military governor. In December, the Treaty of Paris was signed, ending the Spanish-American War and officially approving the cession of Puerto Rico to the United States.
In the first three decades of its rule, the U.S. government made efforts to Americanize its new possession, including granting full U.S. citizenship to Puerto Ricans in 1917 and considering a measure that would make English the island’s official language. However, during the 1930s, a nationalist movement led by the Popular Democratic Party won widespread support across the island, and further U.S. assimilation was successfully opposed. Beginning in 1948, Puerto Ricans could elect their own governor, and in 1952 the U.S. Congress approved a new Puerto Rican constitution that made the island an autonomous U.S. commonwealth, with its citizens retaining American citizenship. The constitution was formally adopted by Puerto Rico on July 25, 1952.
Movements for Puerto Rican statehood, along with lesser movements for Puerto Rican independence, have gained a growing number of supporters on the island. In a 2017 referendum on the island's status, an overwhelming majority voted for statehood.