Originally populated by the indigenous Taino people, the island was claimed in 1493 by Christopher Columbus for Spain during his second voyage. Later it endured invasion attempts from the French, Dutch, and British. Four centuries of Spanish colonial government influenced the island's cultural landscapes with waves of African slaves, Canarian, and Andalusian settlers. In the Spanish Empire, Puerto Rico played a secondary, but strategic role when compared to wealthier colonies like Peru and the mainland parts of New Spain. Spain's distant administrative control continued up to the end of the 19th century, helping to produce a distinctive creole Hispanic culture and language that combined elements from the Native Americans, Africans, and Iberians. In 1898, following the Spanish -- American War, the United States acquired Puerto Rico under the terms of the Treaty of Paris.

Answer this question: when did puerto rico become a part of united states? Let's give stream of consciousness first:
The relevant information is: In 1898, following the Spanish -- American War, the United States acquired Puerto Rico under the terms of the Treaty of Paris.
So, the final answer is 1898.