It was nearing the end of the Spanish-American War in 1898. After 400 years of Spanish colonial domination, Spain had finally granted Puerto Rico it's autonomy through the Carta de Autonomía. As the United States closed in on the island, The Macheteros de Puerto Rico, a loose band of Puerto Rican militants fought to defend the hope of a new nation. With relative success they were able to repel U.S forces.
Spain however, lost the war. With the signing of the Treaty of Paris the U.S laid claim to Puerto Rico even though it was no longer a Spanish territory. Puerto Rico was immediately annexed and without any elections Charles Herbert Allen was appointed the first U.S Governor of Puerto Rico.
Puerto Rico was now a United States colony. At the expense of the Puerto Rican people, Allen opened up the island to U.S business ventures. Allen himself resigned in 1901 so that he could be president of America Sugar Refinery Company, which soon became the largest sugar-refining company in the world. In a 30 year period most of Puerto Rico's arable land had been converted to sugar plantations. American Sugar Refinery Company, which would later be renamed Domino, owned virtually all of these plantations.
A group of members from the Union Party of Puerto Rico separated from the party and joined with two pro-independence organizations. On September 17th , 1922 the Partido Nacionalista de Puerto Rico was formed. Internal strife between leaders over how the party should be run weakened the organization for some years until Pedro Albizu Campos was elected president in 1930. Campos would hold the position until his death in 1965.
Under Campos' direction, the Puerto Rican Nationalist Party became unwavering in its stance for independence and nationalization where other organizations lightened on their views. The Partido Nacionalista de Puerto Rico advocated for the independence of Puerto Rico by any means necessary, including armed force. The Party's revolutionary position would come to have a profound affect on the Puerto Rican people.
As descent against U.S colonial rule increased, pro United States repression intensified. Plan Chardon was a New Deal developmental plan proposed in 1931 by the Chancellor of the University of Puerto Rico. The plan threatened increased U.S control of natural resources and turned the University of Puerto Rico into a U.S propaganda machine.
In opposition to the plan, nationalist students demonstrated on October 24th, 1934 against pro-Chardon supporters. Armed police officers were dispatched to the University by the U.S appointed police chief Colonel Francis Riggs. Once on the scene police officers then fired into the crowd of nationalist demonstrators, killing five people and injuring two in what would be called the Rio Piedras Massacre.
In December of that year Pedro Albizu Campos announced that the Nationalist Party would resign from electoral politics until U.S colonialism ended on the island. In February, 1936, Colonel Riggs was assassinated by nationalist Hiram Rosado and Elias Beauchamp. Both were arrested and subsequently executed at police headquarters without a trial.
On March 21st, 1937, the Nationalist Party organized a peaceful march in Ponce. The Nationalists even requested a legal permit from the Ponce municipality to have the march. What would happen next would be one of the worst atrocities in Puerto Rican history. U.S appointed governor Blanto Winship ordered the new police chief Colonel Enrique de Orbeta to put a stop to the march. The heavily armed Insular Police under the direct military command of the Governor, took position behind the marchers. When the march began to La Borinquena, the Puerto Rican nationalist anthem, police proceeded to fire into the crowd killing 20 civilians and wounding more than 200 people.
The attempted assassination of Blanto Winship and Robert Cooper afterwards only furthered U.S repression of the Nationalist. On June 10th, 1948 , the Puerto Rican legislature under pressure from the United States government approved of Law 53. Under Law 53, also known as Ley de la Mordaza, public displays of Puerto Rican nationalism, the nationalist flag, the nationalist anthem, and even discussions of independence, all became illegal.
On October 30th, 1950, Nationalist hero Blanca Canales led an armed contingency into the city of Jayuya where they staged a successful attack on police headquarters and captured Jayuya. Military airplanes were sent to bomb Jayuya and destroyed 70% of the city. Repression continued on the island in the form of martial law.
On March 1st, 1954, Nationalist hero Lolita Lebron made headlines when she led a Nationalist attack on the United States House of Representatives in a failed attempt to assassinate President Truman. After Pedro Albizu Campos' imprisonment, where he was subject to torture and radiation experiments, the Party's momentum slowly dissipated.
Splinter nationalist groups such as Los Macheteros are still active on the island. Puerto Rico gained common wealth status in 1952 and to this day remains a territory of the United States.