"Economic, Political and Social History of Puerto Rico: From 1898 to 1990" is the result of years of research to obtain a PhD. in History and a Masters in American Foreign Policy. This book intends to deepen in the recent history of Puerto Rico trying to offer answers to some historical questions while providing a detailed vision of the social, economic and political evolution of the Caribbean island. It is hard to believe that a small Caribbean island is still the focus of numerous debates and headaches at the heart of the most powerful country in the world, the United States. At present, while the political status continues to cause heated arguments on the island and on the mainland, Puerto Rico's future remains an enigma that only the United States can resolve.