The party repudiated the "Free Associated State" (Estado Libre Asociado) status that had been enacted in 1950 and which the Nationalists considered a continuation of colonialism.

In a related event, on November 1 of that year, two Nationalists from New York City attempted to storm the Blair House in a failed effort to assassinate U.S. President Harry S. Truman, who supported the Puerto Rican government effort to draft a constitution that would rename the local government as a commonwealth of the United States and provide some limited local autonomy.

[1][2] On March 1, 1954, in another armed assault, four Nationalists fired shots from the visitors' gallery in the House of Representatives of the United States Capitol during a full floor debate, wounding five Congressmen, one seriously.

After 400 years of colonial domination under the Spanish Empire, Puerto Rico received sovereignty in 1898 through a Carta de Autonomía (Charter of Autonomy).

The United States claimed rule over the island under the Treaty of Paris, and the US demanded cessions from its defeated foe, Spain.

The Puerto Rican Nationalist Party arose among opponents to this action, who said that, as a matter of international law, the Treaty of Paris could not empower the Spanish to give what was no longer theirs.

In 1904, the Immigration Service implemented more strict regulations that classified people from Puerto Rico as aliens who tried to enter the US, although previously they had easily migrated.

By 1930 the United Fruit Company owned over one million acres of land in Guatemala, Honduras, Colombia, Panama, Nicaragua, Costa Rica, Mexico and Cuba.

[9] By 1930, over 40 percent of all the arable land in Puerto Rico had been converted into sugar plantations, which were entirely owned by former governor Charles Allen and U.S. banking interests.

Social unrest increased during the Great Depression, and the party became the largest independence movement in Puerto Rico.

In the mid-1930s, the Nationalist movement gained support after the Río Piedras and the Ponce massacres; they said the US-supported government resorted to violence to maintain its colonial regime in Puerto Rico.

[12] The Senate, which at the time was controlled by the Partido Popular Democrático (PPD) and presided by Luis Muñoz Marín, approved the bill.

[14] The Gag Law made it a crime to print, publish, sell, or exhibit any material intended to paralyze or destroy the insular government; or to organize any society, group or assembly of people with a similar destructive intent.

On July 3, 1950, President Harry Truman signed into law the Puerto Rico Federal Relations Act of 1950, as passed by the 81st United States Congress.

It provided for popular elections of the governor, a bicameral legislature and bill of rights, and executive functions similar to those of the states.

They were a call for independence from US rule, demanding the recognition of the 1898 Charter of Autonomy, and Puerto Rico's international sovereignty.

A firefight ensued, killing three Nationalists (Arturo Ortiz, Guillermo González Ubides, José A. Ramos) and wounding six police officers.

After local police arrived, the men escaped into the forests and mountains and avoided further casualties by using guerrilla tactics.

[29] In the incident known as the Gunfight at Salon Boricua, Vidal Santiago Díaz, Albizu Campos' barber, was attacked by 40 police officers and guardsmen.

The incident happened at Santiago Díaz's barbershop, "Salon Boricua", located in the Santurce neighborhood of San Juan.

[30] José Antonio Negrón, a World War II veteran, led the revolt in Naranjito and Nationalists who attacked the police.

They continued to raid several locations until November 6, when the National Guard arrived and attacked the house where the group was staying.

According to an anonymous and undated article in the New York Latino Journal in the early 2000s, it was described at the time in the mainland press as an "incident between Puerto Ricans.

[36] This result was controversial, since the referendum had only offered a choice between the existing colony or commonwealth, and neither independence nor statehood were on the ballot.

The "COINTELPRO program" was a project conducted by the United States Federal Bureau of Investigation (FBI), under J. Edgar Hoover, aimed at surveying, infiltrating, discrediting, and disrupting certain domestic political organizations, including the independence movement in Puerto Rico.

[38] The "Carpetas program" was a massive collection of information gathered by the island's police on so called "political subversives."

[39] Attempt against President Truman U.S. Capitol shooting incident "Mundo Abierto " (Open World) is a poem written in 1956 by Hugo Margenat, in which he refers to the bombardment of the town of Jayuya by the U.S.-backed Puerto Rico National Guard.

y a su calor la patria suspiró transformándose como un rojo beso en el abrazo azul y desnudo del aire.

Sepa usted, Mundo abierto and from its heat the fatherland sighed transforming like a red kiss in the naked and blue hug of the air.

[41] Aguadilla Arecibo Cayey Ciales Corozal Jayuya Juncos Maricao Mayaguez Ponce Naranjito San Juan Utuado Vega Alta