Question: When did the continent on which the mouth of the São Lourenço River can be found become a collection of independent states?

full_context: Document 1: Paraguay River: The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in the Brazilian state of Mato Grosso to its confluence with the Paraná River north of Corrientes and Resistencia.
Document 2: History of South America: The Spanish colonies won their independence in the first quarter of the 19th century, in the Spanish American wars of independence. Simón Bolívar (Greater Colombia, Peru, Bolivia), José de San Martín (United Provinces of the River Plate, Chile, and Peru), and Bernardo O'Higgins (Chile) led their independence struggle. Although Bolivar attempted to keep the Spanish - speaking parts of the continent politically unified, they rapidly became independent of one another.
Document 3: São Lourenço River (Mato Grosso): The São Lourenço River is a tributary of the Paraguay River within the Pantanal, an alluvial plain that spans portions of Brazil, Bolivia and Paraguay.
Document 4: Bermejo River: The Bermejo River (Spanish, Río Bermejo) is a river in South America that flows from Bolivia to the Paraguay River in Argentina. The river is generally called Bermejo in spite of its different names along its way, but it also has its own Native American names; in Wichí it is called Teuco, and in Guaraní it is called Ypitá. In the plains of Argentina's Gran Chaco the Bermejo forms wetlands and splits into two branches. The southern branch is the bed of the old Bermejo River, now an intermittent stream called Río Bermejito. The northern branch is now the main stem of the Bermejo and is called the Teuco River ("Río Teuco"), Bermejo Nuevo, or simply the Bermejo River. The two branches rejoin at , near Villa Río Bermejito, forming the Lower Bermejo River.
Document 5: São Mateus River (Santa Catarina): The São Mateus River (Santa Catarina) is a river of Santa Catarina state in southeastern Brazil. It is part of the Uruguay River basin and a tributary of the Lava-Tudo River.
Document 6: Simón Bolívar: Simón José Antonio de la Santísima Trinidad de Bolívar y Palacios (Spanish: (siˈmon boˈliβar) (listen); 24 July 1783 -- 17 December 1830), generally known as Simón Bolívar and also colloquially as El Libertador, was a Venezuelan military and political leader who played a leading role in the establishment of Venezuela, Bolivia, Colombia, Ecuador, Peru, and Panama as sovereign states, independent of Spanish rule.
Document 7: Decolonization of the Americas: The Latin American wars of independence were the revolutions that took place during the late 18th and early 19th centuries and resulted in the creation of a number of independent countries in Latin America. These revolutions followed the American and French Revolutions, which had profound effects on the British, Spanish, Portuguese, and French colonies in the Americas. Haiti, a French slave colony, was the first to follow the United States; the Haitian Revolution lasted from 1791 to 1804, when they won their independence. From this emerged Napoleon Bonaparte as French ruler, whose armies set out to conquer Europe, including Spain and Portugal in 1808. The Peninsular War with France, which resulted from the Napoleonic occupation of Spain, caused Spanish Creoles in Spanish America to question their allegiance to Spain, stoking independence movements that culminated in the wars of independence, which lasted almost two decades. At the same time, the Portuguese monarchy relocated to Brazil during Portugal's French occupation. After the royal court returned to Lisbon, the prince regent, Pedro, remained in Brazil and in 1822 successfully declared himself emperor of a newly independent Brazil.
Document 8: Tambopata River: The Tambopata River is a river in southeastern Peru and northwestern Bolivia. Most is in the Madre de Dios and Puno regions in Peru, but the upper parts of the river forms the border between Peru and Bolivia, and its origin is in La Paz department in Bolivia. The Tambopata River is a tributary of the Madre de Dios River and merges into this river at the city of Puerto Maldonado. The river flows through the Tambopata National Reserve.
Document 9: Decolonization of the Americas: The Latin American wars of independence were the revolutions that took place during the late 18th and early 19th centuries and resulted in the creation of a number of independent countries in Latin America. These revolutions followed the American and French Revolutions, which had profound effects on the British, Spanish, Portuguese, and French colonies in the Americas. Haiti, a French slave colony, was the first to follow the United States; the Haitian Revolution lasted from 1791 to 1804, when they won their independence. The Peninsular War with France, which resulted from the Napoleonic occupation of Spain, caused Spanish Creoles in Spanish America to question their allegiance to Spain, stoking independence movements that culminated in the wars of independence, which lasted almost two decades. At the same time, the Portuguese monarchy relocated to Brazil during Portugal's French occupation. After the royal court returned to Lisbon, the prince regent, Pedro, remained in Brazil and in 1822 successfully declared himself emperor of a newly independent Brazil.
Document 10: Guaíra, Paraná: Guaíra is a municipality in the state of Paraná in the Southern Region of Brazil. The population is 32,591 (2015 est.) in an area of 560 km². The elevation is 517 m. This place name comes from the Tupi language and means "place difficult to access". The city is served by Guaíra Airport.
Document 11: Paraguay: Paraguay (; ; , ), officially the Republic of Paraguay (; ), is a country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Although it is one of only two landlocked countries in South America (the other is Bolivia), the country has coasts, beaches and ports on the Paraguay and Paraná rivers that give exit to the Atlantic Ocean through the . Due to its central location in South America, it is sometimes referred to as "Corazón de Sudamérica" ("Heart of South America").
Document 12: Decolonization of the Americas: The Latin American wars of independence were the revolutions that took place during the late 18th and early 19th centuries and resulted in the creation of a number of independent countries in Latin America. These revolutions followed the American and French Revolutions, which had profound effects on the British, Spanish, Portuguese, and French colonies in the Americas. Haiti, a French slave colony, was the first to follow the United States; the Haitian Revolution lasted from 1791 to 1804, when they won their independence. The Peninsular War with France, which resulted from the Napoleonic occupation of Spain, caused Spanish Creoles in Spanish America to question their allegiance to Spain, stoking independence movements that culminated in the wars of independence, which lasted almost two decades. At the same time, the Portuguese monarchy relocated to Brazil during Portugal's French occupation. After the royal court returned to Lisbon, the prince regent, Pedro, remained in Brazil and in 1822 successfully declared himself emperor of a newly independent Brazil. Cuban independence was fought against Spain in two wars (Ten Years and Little War). Cuba and Puerto Rico remained under Spanish rule until the Spanish -- American War in 1898.
Document 13: Paraná Valles: Paraná Valles is a valley in the Margaritifer Sinus quadrangle (MC-19) region of Mars, located at approximately 23.1° South and 10.2° West. It is 350 km long and was named after an ancient and modern name for a South American river (Brazil, Argentina). A low area between Paraná Valles and Loire Valles is believed to have once held a lake.
Document 14: Solimões River: Solimões () is the name often given to upper stretches of the Amazon River in Brazil from its confluence with the Rio Negro upstream to the border of Peru. At the confluence, the river is already by far the largest river in the world, even though its two largest tributaries have not yet entered (the Negro and the Madeira River). The Solimões portion of the Amazon river lies entirely in the State of Amazonas, Brazil, and some portion of the state is often referred to as the "Solimões region". The ecoregion of the Solimões river drainage basin is entirely tropical rainforest.
Document 15: Guaporé River: Guaporé River (Portuguese: Rio Guaporé) is a river in western Brazil and northeastern Bolivia. Its Bolivian name is Río Iténez. It is 1,530 km (950 mi) long; 970 km (600 mi) of the river forms the border between Brazil and Bolivia.
ground_truth: the first quarter of the 19th century
sub_queries: São Lourenço River >> mouth of the watercourse Answer: Paraguay River
Which continent is Paraguay River on? Answer: South America
South America became a collection of independent states between Answer: the first quarter of the 19th century