The desire to reach across the Atlantic the easternmost lands of Asia which had prompted C. Columbus to his glorious feat and provoked the famous voyages of the Vespucci along such a great stretch of the coast of South America, became more ardent after the Balboa had revealed the existence of the South Sea (1513); indeed, the problem of the newly discovered passage from the Atlantic to the sea dominated all the explorations of the first half of the century. XVI. So he went in search of the famous passage Juan Díaz de Solís which, having succeeded Vespucci in the position of pilot mayor of Castile, was the first (as far as we know) to approach the current banks of Argentina by penetrating the Platense estuary, which he called Mar Dulce ; but his companions baptized him with the name of Río de Solís after his tragic death, perished there on the Uruguayan coast by the ferocious Charrúas (1516). With the same intention of finding a passage to the South Sea, in 1520 F. Magellano explored both the estuary of the Río de Solís and the Argentine and Patagonian coast, indeed in Porto S. Giuliano, in Patagonia, the Magellan wintered before ‘enter the strait that bears his name. The expedition led by Sebastiano Caboto, named pilot mayor, was also directed to the solution of the famous problemin 1518 in place of the Solís. Leaving Sanlucar on 5 April 1526, the Cabotus entered the great estuary discovered by the Solís in February 1527; there he learned of an internal empire rich in gold and silver and therefore decided to enter the river. From May 1527 to the end of 1529 he went up for a stretch of Uruguay, then Paraná and Paraguay up to the confluence of the Pilcomayo (called by the Caboto Río de la Trajicion), looking in vain for the mineral riches of which he had announced to the king of Spain and who had earned the estuary the name of Río de la Plata. The journey of the Cabotus, if it was almost a disaster from the commercial point of view, was able to specify in its broad lines the Platense river system, as appears from the maps of the time.
Some Spaniards, attracted by the mirage of mineral wealth, and above all Pedro de Mendoza, who organized a large expedition to colonize the banks of the Plata at his own expense, boldly set out on the road opened by the Caboto. Appointed in 1534 adelantado (governor) of the territories he would have occupied, he landed in January 1535 on the right bank of the Plata where on February 2 he laid the foundations of the city of Santa María de Buenos Aires; the colony could not prosper at the time, on the contrary it was abandoned due to the hostility of the natives. Meanwhile, the lieutenant of Mendoza, Juan de Ayolas, went up again Paraná-Paraguay and in 1536 founded Asunción which was to soon become the center of Spanish colonization in the southern provinces of America. The Ayolas, continuing the navigation on Paraguay up to the latitude of 20 ° S., tried to reach Peru through the Bolivian Chaco (1537), but on the way back he was killed by the Indians; his companion and substitute Domingo Martínez Irala later repeated (1548) the crossing from Paraguay to Peru,
In the second half of the century. XVI geographic knowledge proceeded hand in hand with colonization and the various cities then founded mark the stages of the conquest. Thus Santiago del Estero was founded by Aguirre in 1553; Mendoza from Hurtado de Mendoza in 1560, Tucumán from Villaroel in 1565; Córdoba from Cabrera in 1573; Jump from de Lerma in 1582; Corrientes in 1588 by Alonso de Vera, while Buenos Aires was rebuilt by Juan de Garay in 1580. The Jesuit missions, established first in Tucumán and then in Paraguay, completely organized under the direction of the Society of Jesus the northern territory largely explored by the P Manuel de Ortega (1587).
In the colonial period from 1560 to 1800 the progress of exploration and colonization remained very poor also because the territories of the Plata depended on the viceroy of Peru, who managed for a long time to prevent direct trade between Buenos Aires and the metropolis: the goods had to follow the road to Lima along the great colonial road that led to Tucumán and Salta on the Bolivian plateau.
Worth mentioning are the first explorations in Patagonia carried out by the Spaniards Basilio Villarino, who went up the Río Negro to search for a passage to Chile (1782), and Viedma who crossed the southern plain from the Gulf of S. Giuliano to Lake Viedma (1782) ; the hydrographic surveys carried out in the Plata estuary by Alessandro Malaspina di Mulazzo, who in his famous expedition also explored the Patagonian coast from Río Negro to Puerto Deseado (1789); and the very important work of Felice de Azara who, as commissioner for the determination of the Spanish-Portuguese borders established by the treaty of Sant’Idelfonso (1778), lived for twenty years (1781-1801) in the southern Spanish possessions along the various regions of the interior, studying their geography and natural history:
The Platensian provinces had recently been erected in viceroyalty (1776) when the fortunate European events during the French Revolution and the Napoleonic Empire provoked the rebellion of the Spanish colonies, but first the war of independence and then the civil discords, which in the Argentina ravaged the first period of freedom, they greatly limited the work of the explorers, so that it will suffice to mention the exploration (1827-30) of the southern coasts and especially of Tierra del Fuego by Filippo Parker King and Roberto Fitz Roy who were accompanied by young Carlo Darwin (see Journey of a naturalist around the world), and those of the Italian Nicola de ‘Scalzi, who in 1821 took over the course of the Río Benuejo and in 1833 that of the Río Negro on the Patagonian borders. The scientific knowledge of the interior, on the other hand, expands rapidly in the second half of the century. XIX, when the new republic, obtained the internal pacification, favors the exploration and the valorization of the very wide territory. Among the many scholars we will limit ourselves to pointing out the most important, and we will first remember Ermanno Burmeister who can be considered the father of naturalist explorers and geographers of Argentina. Arrived in 1856 in the states of Plata after visiting southern Brazil, this illustrious scientist began to travel the plain between the two rivers and then crossed the Andean mountain range in the direction of Copiapó (1859). Physikalische Beschreibung der Argentinischen Republik, Buenos Aires 1875 ff. For Argentina 2017, please check mathgeneral.com.
Also of great interest were the reconnaissance of the Paraná and Paraguay rivers carried out from 1853 to 1859 by Captain Tommaso Page of the US Navy, and the explorations of Martino de Moussy who visited the pampas up to the Río Negro on behalf of the government and published in Paris over the years 1860-64 a Déscription géographique et statistique de la Confédération Argentine. Burmeister’s disciples were Argentina Stelzner and L. Brackebusch, professors at the University of Córdoba, who particularly studied geography and geology, the first of the Andes and the pampas north and south of Córdoba (1872-74), the second of the whole territory between Chile and Plata, from Juiuy to Río Atuel in the province of Mendoza. Opera del Brackebuxh is also the large map of the Argentine Republic at a scale of 1: 1,000,000 in 13 sheets. In the meantime, the topographical surveying works by or with the collaboration of the Argentine government began, and numerous scientists studied the constitution and the geographical, morphological and geological aspects of the pampas and the Andean Cordillera. The works of FP Moreno, Edoardo Aguirre, Pietro N. Arata, Carlo Berg, Angelo Gallardo, GB Ambrosetti, Carlo Spegazzini, Gaetano Rovereto and many others led to an almost complete knowledge of the Argentine territory.
Patagonia, on the other hand, remained closed for a long time to exploration and colonization, where the ferocious natives with cruel energy opposed the attempts of travel and the penetration of the Jesuit missionaries, Mascardi, Laguna, Guililermos, Elguea, martyrs of the faith. Only after the Argentine government proceeded to occupy the territory with a regular campaign lasting two years (1879-80), Patagonia too could be completely known and largely civilized thanks especially to the Salesian missionaries sent by St. John Bosco (1880).). Before 1879, the Englishman Giorgio Musters (1869-70) had crossed the whole region from Punta Arenas, on the Strait of Magellano, to Carmen de Patagones, on the lower Río Negro; his report published in London in 1871 (At home with the Patagonians) gave news of completely unknown regions and important information about the Patagons. Then the Berg and the Moreno in 1874-75 explored the basins of the Río Negro and the Río Santa Cruz; the Moreno going up the latter river reached Lake Argentino and took over its communications with Lake Viedma and Lake San Martín; in 1877 J. Rogers and E. Ibar traveled the southern part from the Strait of Magellan to Lake Argentino providing important observations on the White Lagoon, on the Río Gallegos, and on the stature of the Patagons. After the military occupation, explorations and travels multiplied; Particular importance deserves the work of Colonel L. Fontana who was part of the conquest expedition and therefore remained at the head of one of the territories.
After 1890 the southern cordillera south of the 40th parallel was the subject of detailed and exhaustive study on the occasion of the conflict between Chile and Argentina for the delimitation of the political border. The works of H. Steffen and his collaborators P. Stange and P. Krüger on the Chilean side (1892-1900) and of FP Moreno on the eastern side shed clear light on the complicated morphology of that tormented region. The reports, plans and papers presented by the two governments to the Arbitral Tribunal in support of their respective claims (1900) constitute a valuable source for the study of Southern Patagonia.
In closing this review we must also speak of the explorations in Tierra del Fuego: it is enough to mention that of M. Pertuiset (1873); to the Argentine-Italian expedition (1882) directed by Lieutenant Giacomo Bove with the participation of Roniagli, Spegazzini, Lovisato and Vinciguerra; to the Argentine expedition commanded by Ramón Lista (1887) and to the remarkable recent work of the Salesian Alberto De Agostini.