Puerto Rican citizenship
In 1952, upon U.S. Congress approving the Constitution of the Commonwealth of Puerto Rico, also reaffirmed that Puerto Rican citizenship continued in full force. This was further reaffirmed in 2006 while the U.S. Senate probed into the President's Task Force on Puerto Rico's status. In 1953, U.S Ambassador Henry Cabot Lodge Jr., in a memorandum sent to the United Nations, recognized that "the people of Puerto Rico continue to be citizens of the United States as well as of Puerto Rico."
Puerto Ricans in the United States
Since 1898, Puerto Rico has been under the control of the United States, fueling migratory patterns between the mainland and the island. Even during Spanish rule, Puerto Ricans settled in the US. However, it was not until the end of the Spanish–American War in 1898 that a significant influx of Puerto Rican workers to the US began. With its 1898 victory, the United States acquired Puerto Rico from Spain and has retained sovereignty since. The 1917 Jones–Shafroth Act made all Puerto Ricans US citizens, freeing them from immigration barriers. The massive migration of Puerto Ricans to the mainland United States was largest in the early and late 20th century, prior to its resurgence in the early 21st century.