How did Puerto Rico become a US Territory?

Since the Spanish-American War in 1898, the US has held Puerto Rico, which was formally given to it as a colony and territory in the Treaty of Paris in 1899. The relationship has gone through different stages, sometimes leading to tensions between the territory's leaders and the US government.

US Interests in Puerto Rico

United States interests in Puerto Rico, and the wider Caribbean for that matter, had increased to a high level by 1890, as the US emerged as a major naval power. By this time, there were interests to acquire Panama or another nearby country to create the Panama canal, while others in the US government had advocated for Caribbean bases such as Cuba and Puerto Rico. By 1894, the Naval War College had anticipated that war with Spain, which had controlled Puerto Rico and Cuba, would likely occur. Puerto Rico's valuable sugar crops were also of interest, particularly as the sugar industry was not developed within the US. On February 15, 1898, the USS Maine mysteriously sank, after having been dispatched to monitor events in Cuba which had revolted against Spain. This led the US to declare war and resulted in a relatively quick victory as the US had decisive naval power. On July 25, 1898 (Figure 1), US forces landed near Guánica, Puerto Rico. To this day, this landing is commemorated as Constitution Day in Puerto Rico, which was previously called Occupation Day as the start of the US presence on the island. After the US landing, military action continued until August 13, 1898, but the fighting was inconclusive for all sides. However, by this time, an armistice was signed and the US was left in control of the entire island on the agreements made in the Treaty of Paris that officially concluded the Spanish-American War.[1]

Figure 1. The US landing on Puerto Rico on July 25, 1898.

US Territory

At the beginning of the 20th century, Puerto Rico was effectively ruled by a military governor appointed by the President. The Foraker Act in 1900 gave Puerto Rico limited ability to control its sovereignty by establishing a 35-member House of Representatives for the island. A judicial system was also established with one US non-voting representative assigned. The US could still appoint the governor and Upper House in the legislative system. The new Act did enable Puerto Rico to enact its own laws, but any of these laws could be overturned by the US government. Additionally, the US enacted the Hollander Tax on land holdings in Puerto Rico, mainly targeting medium and large land holdings. The tax was minimal, later revised to 1%, but it did cause a lot of animosity in the early years of US administration as it was enacted without Puerto Rican approval and borrowing rates for land had increased. In the early years after the US had been given Puerto Rico, there was a wide-spread independence movement, similar to Cuba and other former Spanish colonies. This continued after the US possession of the island and in 1914 the House of Representatives in Puerto Rico voted unanimously for independence from the US. However, the US government saw this vote as unconstitutional and a violation of the Foraker Act that had established the legislative parameters for Puerto Rico, rejecting the independence vote.[2]

The results of the initial vote for independence from the US led to friction and hostility between government officials who were elected and those appointed to govern the island by the US President and government. In 1917, the Jones–Shafroth Act was enacted, which granted citizenship to Puerto Rico's citizens born after April 25, 1898. This led to further friction because it was seen as plot by the elected officials as an attempt to draft Puerto Rico's residents into World War I. However, the Act did also expand some of the rights Puerto Ricans could have by enabling an elected Senate and bill of rights to govern the island's citizens. With the onset of the Great Depression, and disasters including hurricanes, Puerto Rico's economy decline by 1930. This, once again, led to increased interest in an independence movement in Puerto Rico. The populist leader Pedro Albizu Campos, leader of the Puerto Rican Nationalist Party, arose to prominence. The 1930s became a period of political conflict in Puerto Rico. The US-appointed governor attempted to repress the party, but the party responded by assassinating two politicians. In the 1930s, as independence for the Philippines was gaining popularity in the US Senate, the US Senate sponsored a bill giving Puerto Rico independence. Luis Muñoz Marín, of the Puerto Rican Liberal Party, however, opposed the bill, leading to its defeat in Puerto Rico, despite the majority of other parties and legislators agreeing to the bill. Puerto Rico had become divided into two main political camps, with those supporting and opposing the presence of the US. Two massacres during peaceful protests, including the well publicized Ponce massacre (Figure 2) that led to 19 civilian deaths, in the late 1930s led to more anti-US sentiment, leading once again the US congress to introduce a bill for independence in 1943. Once again, it was defeated by pro-US opposition in Puerto Rico. The late 1930s and early 1940s became a tense period as the local police and national guards, seen as favoring the US administrator, became a focus of protest and fear for Puerto Rican nationalists. The Elective Governor Act, passed in 1948, finally allowed local election for Puerto Rico's governor, with Luis Muñoz Marín becoming the first elected governor. However, the Partido Popular Democrático, controlled by Marín, effectively attempted to outlaw any Puerto Rican independence movement by making their advertising and organization largely illegal. In 1950, Puerto Rico gained its right to form its own constitution. The period of tension with the US perhaps culminated with an attempted assassination of President Truman by Puerto Rican nationalists Oscar Collazo and Griselio Torresola, with Torresola killed in the attempt and Collazo later being commuted in his sentence after the failed assassination attempt.[3]

Figure 2. The Ponce massacre.

Recent History

Since 1952, Puerto Rico had a defined constitution and since then its economy has transformed from an agricultural one to a manufacturing and tourism economy, with the service sector dominating in recent years. The second half of the twentieth century also saw an increasing and growing statehood movement. Since the 1950s, Puerto Rico's relationship with the United States was defined as a commonwealth entity, with the US having overall rule on the island in relation to defense, foreign policy, and many other areas, including citizenship for islanders. Since the 1960s, Puerto Rico has held periodic referendums to vote on statehood, independence, or commonwealth status in defining its relationship with the US. Both the 1998 and 2012 referendums showed that the majority of Puerto Ricans wanted to be granted statehood in the United States. However, the results were not accepted as the US Congress has the authority to accept the results. In both these referendums, there were many blank ballots or choices for 'none of the above' in regards to independence, statehood, or continuing the commonwealth status. These results were considered by Congress to be unclear, leading to Congress not fully taking up the issue Puerto Rico's statehood. The 2017 referendum resulted in a 97% result for statehood, but since only 23% of the eligible population voted and the Justice Department had not approved the referendum's language, leading to no commitment on the part of the US government on the results. Since 2016, the United Nations has called on the US government to clear up the statue of Puerto Rico, allowing its self-determination, and has called Puerto Rico effectively a colony. In fact, today Puerto Rico is often called the World's oldest and most long-lived colony.[4]


Puerto Rico is among a handful of US territories where laws and protection afforded to US citizens are not the same given that the island has very limited political independence. Recent efforts have attempted to clarify the relationship between Puerto Rico and the US, but for a variety of reasons this has not been successful. The historical legacy of Puerto Rico over the last 500 years has been seen as colonialism by the UN. Efforts continue to clarify the relationship between the US and Puerto Rico and a future referendum is planned in 2020.


  1. For more on early interests in Puerto Rico, see: Figueroa, L.A., 2005. Sugar, slavery, & freedom in nineteenth-century Puerto Rico. University of North Carolina Press, Chapel Hill.
  2. For more on the early years after the US takeover of Puerto Rico, see: Duany, J., 2017. Puerto Rico: what everyone needs to know. Oxford University Press, New York, NY.
  3. For more on Puerto Rican nationalists movements after the US takeover of the island, see: Denis, N.A., 2015. War against all Puerto Ricans: revolution and terror in America’s colony. Nation Books, A Member of the Perseus Books Group, New York, NY.
  4. For more on recent political changes in Puerto Rico, see: Ayala, C.J., Bernabe, R., 2009. Puerto Rico in the American century: a history since 1898. University of North Carolina Press, Chapel Hill.