October 12, 1739: The town of Utuado was founded.

October 7, 1775: Ramon Power, considered by many to be the first Puerto Rican patriot, was born. Where many of his countrymen considered themselves Spaniards who happened to be born in Puerto Rico, he called himself a Puerto Rican. He represented Puerto Rico in the Spanish Cortes, where he worked hard to further the island's interests.

October 6, 1822: Manuel Alonso, a physician and writer was born. He has been called the first noteworthy Puerto Rican writer.

October 27, 1880: First colonists arrived in Culebra.

October 18, 1898: Following the Spanish-American war, the official transfer of power from Spain to the United States took place in San Juan. The same day, Major General John Brooke was named the first American Governor of Puerto Rico.

October 11, 1966: The first Puerto Rican Research Library in the United States was established in New York City.