Answer:
After the Spanish-American War
Step-by-step explanation:
Puerto Rico was acquired by the United States in 1898, which was near the end of the Spanish-American War. The Spanish-American War began in 1898 and it was a fight over colonies in the Americas between the United States and Spain. Ultimately, the United States won, and was able to free colonial territories from Spanish rule, one of which being Puerto Rico. However, near the end of the war, the United States invaded Puerto Rico successfully, establishing control. This was to attack the Spanish forces, but it's argued that it was also because the United States had interests in establishing control on the island. Hence, with the success, the United States was able to acquire Puerto Rico soon after the end of this war, as it was a term in the Treaty of Paris. Puerto Rico was devastated, as they believed that they were freed from colonial control, yet their freedom lasted a mere couple of months.