Question: When did the territory that has been suggested as new addition to the United States gain independence from Spain?

full_context: Document 1: Independence movement in Puerto Rico: After four hundred years of colonial rule by the Spanish Empire, Puerto Rico finally received its sovereignty in 1897 through a Carta de Autonomía (Charter of Autonomy). It was signed by Spanish Prime Minister Práxedes Mateo Sagasta and ratified by the Spanish Cortes.
Document 2: 51st state: Several days after the referendum, the Resident Commissioner Pedro Pierluisi, Governor Luis Fortuño, and Governor-elect Alejandro García Padilla wrote separate letters to the President of the United States Barack Obama addressing the results of the voting. Pierluisi urged Obama to begin legislation in favor of the statehood of Puerto Rico, in light of its win in the referendum. Fortuño urged him to move the process forward. García Padilla asked him to reject the results because of their ambiguity. The White House stance related to the November 2012 plebiscite was that the results were clear, the people of Puerto Rico want the issue of status resolved, and a majority chose statehood in the second question. Former White House director of Hispanic media stated, "Now it is time for Congress to act and the administration will work with them on that effort, so that the people of Puerto Rico can determine their own future."
Document 3: History of Puerto Rico: On August 10, 1815, the Royal Decree of Grace was issued, allowing foreigners to enter Puerto Rico (including French refugees from Hispaniola), and opening the port to trade with nations other than Spain. This was the beginning of agriculture-based economic growth, with sugar, tobacco, and coffee being the main products. The Decree also gave free land to anyone who swore their loyalty to the Spanish Crown and their allegiance to the Roman Catholic Church. Thousands of families from all regions of Spain (particularly Asturias, Catalonia, Majorca and Galicia), Germany, Corsica, Ireland, France, Portugal, the Canary Islands and other locations, escaping from harsh economic times in Europe and lured by the offer of free land, soon immigrated to Puerto Rico. However, these small gains in autonomy and rights were short lived. After the fall of Napoleon, absolute power returned to Spain, which revoked the Cádiz Constitution and reinstated Puerto Rico to its former condition as a colony, subject to the unrestricted power of the Spanish monarch.
Document 4: History of Puerto Rico: Located in the northeastern Caribbean, Puerto Rico formed a key part of the Spanish Empire from the early years of the exploration, conquest and colonization of the New World. The island was a major military post during many wars between Spain and other European powers for control of the region in the 16th, 17th and 18th centuries. The smallest of the Greater Antilles, Puerto Rico was a stepping - stone in the passage from Europe to Cuba, Mexico, Central America, and the northern territories of South America. Throughout most of the 19th century until the conclusion of the Spanish -- American War, Puerto Rico and Cuba were the last two Spanish colonies in the New World; they served as Spain's final outposts in a strategy to regain control of the American continents. Realizing that it was in danger of losing its two remaining Caribbean territories, the Spanish Crown revived the Royal Decree of Graces of 1815. The decree was printed in Spanish, English and French in order to attract Europeans, with the hope that the independence movements would lose their popularity and strength with the arrival of new settlers. Free land was offered to those who wanted to populate the islands on the condition that they swear their loyalty to the Spanish Crown and allegiance to the Roman Catholic Church.
Document 5: Puerto Rico: Originally populated by the indigenous Taíno people, the island was claimed in 1493 by Christopher Columbus for Spain during his second voyage. Later it endured invasion attempts from the French, Dutch, and British. Four centuries of Spanish colonial government influenced the island's cultural landscapes with waves of African slaves, Canarian, and Andalusian settlers. In the Spanish Empire, Puerto Rico played a secondary, but strategic role when compared to wealthier colonies like Peru and the mainland parts of New Spain. Spain's distant administrative control continued up to the end of the 19th century, helping to produce a distinctive creole Hispanic culture and language that combined elements from the Native Americans, Africans, and Iberians. In 1898, following the Spanish -- American War, the United States acquired Puerto Rico under the terms of the Treaty of Paris.
Document 6: 51st state: The Washington Post, The New York Times and the Boston Herald have published opinion pieces expressing support for the statehood of Puerto Rico. On November 8, 2012, Washington, D.C. newspaper The Hill published an article saying that Congress will likely ignore the results of the referendum due to the circumstances behind the votes. and U.S. Congressman Luis Gutiérrez U.S. Congresswoman Nydia Velázquez, both of Puerto Rican ancestry, agreed with the The Hill 's statements. Shortly after the results were published Puerto Rico-born U.S. Congressman José Enrique Serrano commented "I was particularly impressed with the outcome of the 'status' referendum in Puerto Rico. A majority of those voting signaled the desire to change the current territorial status. In a second question an even larger majority asked to become a state. This is an earthquake in Puerto Rican politics. It will demand the attention of Congress, and a definitive answer to the Puerto Rican request for change. This is a history-making moment where voters asked to move forward."
Document 7: 51st state: Puerto Rico has been discussed as a potential 51st state of the United States. In a 2012 status referendum a majority of voters, 54%, expressed dissatisfaction with the current political relationship. In a separate question, 61% of voters supported statehood (excluding the 26% of voters who left this question blank). On December 11, 2012, Puerto Rico's legislature resolved to request that the President and the U.S. Congress act on the results, end the current form of territorial status and begin the process of admitting Puerto Rico to the Union as a state.
Document 8: Puerto Rico: Originally populated by the indigenous Taíno people, the island was claimed in 1493 by Christopher Columbus for the Crown of Castile during his second voyage. Later it endured invasion attempts from the French, Dutch, and British. Four centuries of Spanish colonial government transformed the island's ethnic, cultural and physical landscapes primarily with waves of African slaves, and Canarian, and Andalusian settlers. In the Spanish imperial imagination, Puerto Rico played a secondary, but strategic role when compared to wealthier colonies like Peru and the mainland parts of New Spain. Spain's distant administrative control continued up to the end of the 19th century, helping to produce a distinctive creole Hispanic culture and language that combined elements from the Native Americans, Africans, and Iberians. In 1898, following the Spanish -- American War, the United States acquired Puerto Rico along with other Spanish colonies under the terms of the Treaty of Paris.
Document 9: 51st state: On May 15, 2013, Resident Commissioner Pierluisi introduced H.R. 2000 to Congress to "set forth the process for Puerto Rico to be admitted as a state of the Union," asking for Congress to vote on ratifying Puerto Rico as the 51st state. On February 12, 2014, Senator Martin Heinrich introduced a bill in the US Senate. The bill would require a binding referendum to be held in Puerto Rico asking whether the territory wants to be admitted as a state. In the event of a yes vote, the president would be asked to submit legislation to Congress to admit Puerto Rico as a state.
Document 10: 51st state: In November 2012, a referendum resulted in 54 percent of respondents voting to reject the current status under the territorial clause of the U.S. Constitution, while a second question resulted in 61 percent of voters identifying statehood as the preferred alternative to the current territorial status. The 2012 referendum was by far the most successful referendum for statehood advocates and support for statehood has risen in each successive popular referendum. However, more than one in four voters abstained from answering the question on the preferred alternative status. Statehood opponents have argued that the statehood option garnered only 45 percent of the votes if abstentions are included. If abstentions are considered, the result of the referendum is much closer to 44 percent for statehood, a number that falls under the 50 percent majority mark.
Document 11: Puerto Rico: Originally populated by the indigenous Taíno people, the island was claimed in 1493 by Christopher Columbus for the Crown of Castile during his second voyage. Later it endured invasion attempts from the French, Dutch, and British. Four centuries of Spanish colonial government transformed the island's ethnic, cultural and physical landscapes primarily with waves of African slaves, Canarian, and Andalusian settlers. In the Spanish imperial imagination, Puerto Rico played a secondary, but strategic role when compared to wealthier colonies like Peru and the mainland parts of New Spain. Spain's distant administrative control continued up to the end of the 19th century, helping to produce a distinctive creole Hispanic culture and language that combined elements from the Native Americans, Africans, and Iberians. In 1898, following the Spanish -- American War, the United States acquired Puerto Rico under the terms of the Treaty of Paris.
Document 12: Statehood movement in Puerto Rico: The statehood movement in Puerto Rico aims to make Puerto Rico a state of the United States. Five referenda have been held on the topic, most recently in 2017. The population of Puerto Rico as of 2015 was over 3 million people and larger than 21 states.
Document 13: Puerto Rico: Originally populated by the indigenous Taíno people, the island was claimed in 1493 by Christopher Columbus for Spain during his second voyage. Later it endured invasion attempts from the French, Dutch, and British. Four centuries of Spanish colonial government influenced the island's cultural landscapes with waves of African slaves, Canarian, and Andalusian settlers. In the Spanish Empire, Puerto Rico played a secondary, but strategic role when compared to wealthier colonies like Peru and the mainland parts of New Spain. Spain's distant administrative control continued up to the end of the 19th century, helping to produce a distinctive creole Hispanic culture and language that combined elements from the Native Americans, Africans, and Iberians. In 1898, following the Spanish -- American War, the United States acquired Puerto Rico under the terms of the Treaty of Paris. The treaty took effect on April 11, 1899.
Document 14: Puerto Rico: Puerto Ricans are by law citizens of the United States and may move freely between the island and the mainland. As it is not a state, Puerto Rico does not have a vote in the United States Congress, which governs the territory with full jurisdiction under the Puerto Rico Federal Relations Act of 1950. However, Puerto Rico does have one non-voting member of the House called a Resident Commissioner. As residents of a U.S. territory, American citizens in Puerto Rico are disenfranchised at the national level and do not vote for president and vice president of the United States, and do not pay federal income tax on Puerto Rican income. Like other territories and the District of Columbia, Puerto Rico does not have U.S. senators. Congress approved a local constitution in 1952, allowing U.S. citizens on the territory to elect a governor. A 2012 referendum showed a majority (54% of those who voted) disagreed with ``the present form of territorial status ''. A second question asking about a new model, had full statehood the preferred option among those who voted for a change of status, although a significant number of people did not answer the second question of the referendum. A fifth referendum was held on June 11, 2017, with`` Statehood'' and ``Independence / Free Association ''initially as the only available choices. At the recommendation of the Department of Justice, an option for the`` current territorial status'' was added. The referendum showed an overwhelming support for statehood, with 97.18% voting for it, although the voter turnout had a historically low figure of only 22.99% of the registered voters casting their ballots.
Document 15: 51st state: Puerto Rico has been under U.S. sovereignty for over a century when it was ceded to the U.S. by Spain following the end of the Spanish–American War, and Puerto Ricans have been U.S. citizens since 1917. The island's ultimate status has not been determined as of 2012[update], its residents do not have voting representation in their federal government. Puerto Rico has limited representation in the U.S. Congress in the form of a Resident Commissioner, a delegate with limited no voting rights. Like the states, Puerto Rico has self-rule, a republican form of government organized pursuant to a constitution adopted by its people, and a bill of rights.
ground_truth: 1897
sub_queries: What territory has been suggested as a new addition to the United States? Answer: Puerto Rico
when did Puerto Rico gain their independence from spain Answer: 1897