Puerto Rico became part of the United States in 1898 , when Spain ceded the island to the U.S. after the Spanish‑American War under the Treaty of Paris.

Quick timeline

  • July 25, 1898 – U.S. troops land in Puerto Rico during the Spanish‑American War.
  • October 18, 1898 – U.S. forces formally take control and raise the U.S. flag on the island.
  • December 10, 1898 – The Treaty of Paris is signed; Spain formally cedes Puerto Rico to the U.S.
  • May 1900 – The Foraker Act sets up a U.S. civil government in Puerto Rico, confirming its status under U.S. rule.
  • March 2, 1917 – The Jones–Shafroth Act declares Puerto Rico a U.S. territory and grants U.S. citizenship to Puerto Ricans born on or after April 25, 1898.
  • 1952 – Puerto Rico adopts its own constitution and becomes a U.S. commonwealth (still a territory, not a state).

So, in simple terms:

  • Puerto Rico came under U.S. control in 1898 (Treaty of Paris).
  • It was formally made a U.S. territory and its people granted U.S. citizenship in 1917 (Jones–Shafroth Act).

Information gathered from public forums or data available on the internet and portrayed here.