With the eighteenth century Spain adopted a little more liberal policy toward her colonies in regard to trade. The prestige which England and Holland had obtained practically forced certain concessions. Uruguay began to be settled by Spaniards. The increase in population and greater demand for wool and hides in Europe caused a remarkable advance in trade. In 1767 the Jesuits were expelled, as they had been in Brazil some time previous. This order had accumulated enormous wealth and ruled a large section of the country with an iron hand. The members of the order were forcibly driven out and their property sold at auction or divided among other orders.

In 1776, just a few days after the declaration of independence in the American colonies, Buenos Aires was established as a viceroyalty. Lake Titicaca on the north, and the Andes on the west, were established as the boundary lines. It included the territory now divided into the four republics of Uruguay, Bolivia, Argentina and Paraguay. South of the city of Buenos Aires, however, there was practically no development. The first viceroy was named Pedro de Zeballos, who came over with a large force of soldiers and sailors in order to drive out the Portuguese. Free commerce with Spain was now permitted and commerce greatly increased. Buenos Aires became the centre of all this trade, was greatly prospered and its population rapidly increased. Wines, brandies, hides, tobacco and maté (Paraguay tea) were the principal articles exported to Europe.

The beginning of the nineteenth century saw unrest all over South America. It began in Quito, Ecuador, and spread in every direction. It did not take long to reach the loosely cohered sections of the viceroyalty of Buenos Aires, in which the different elements had not coalesced. The Spaniards generally lived in the populated centres, while the gauchos, mostly half-breeds, had their homes on the broad pampas. It was essentially democratic as compared with more aristocratic Peru and Mexico. The only common bond was religion, and that was not strong. Spain’s selfish policy had destroyed her prestige, while the revolutions in France and North America had propagated the idea of democracy among the youth.

Perhaps no one incident had greater influence upon the final events than the attempt of England, encouraged by her successes in South Africa, to capture Buenos Aires. In June, 1806, a British fleet bearing on board fifteen hundred troops appeared in the La Plata. The Viceroy immediately fled, and the British flag soon floated over his late residence. For several weeks the people acquiesced in this change, but a Frenchman, named Jacques de Liniers, headed the opposition. He organized a force in Montevideo and advanced on Buenos Aires. The citizens, reanimated by his enthusiasm, flocked to his banner and, after some bloody street fighting, the English were compelled to surrender. Their flags were captured and are still exhibited as trophies of Argentine prowess in the Church of Santo Domingo in that city. The success of the Argentinos, who had accomplished this victory without help from the mother country, greatly encouraged the patriots and aroused in them a hope of separation from Spain. Reinforcements came from England, to renew the conflict. The troops marched confidently into the city. The flat roofs of the buildings and the parapet-like fronts, however, provided excellent shelter for the defenders, and the British general was finally compelled to ask for terms. He had lost a quarter of his force but was allowed to leave on honourable terms. The attempt of Napoleon to place his brother, Joseph Bonaparte, on the throne of Spain also fermented the spirit of revolution that was becoming rampant, for the people felt no loyalty or allegiance to this upstart. A new Viceroy was sent out by the mother country, but he did not remain in peace very long. In an effort to placate the Spanish-American colonies a royal decree was issued that the colonies were considered an integral part of the monarchy and should have representatives in the Cortes. “At last you are raised to the dignity of free men,” came the message to the colonists. It was too late.

A group of patriots had already risen who were holding meetings to decide what could be done in this crisis. The leader in this band was Manuel Belgrano. They decided to ask the resignation of the Viceroy and waited on him with this request. He knew that his position was untenable because of the disaffection among the troops. On the 25th of May, 1810,[2] an armed assembly met on the plaza in front of the government palace under the leadership of Belgrano, Moreno, Castelli and Valcarcel. The colours of blue and white were seen everywhere, for these were the colours adopted by the revolutionists. A provisional junta was selected who assumed the executive powers of government. For several years, however, their acts all run in the name of Ferdinand VII, King of Castile and Leon. No attempt was made at this time to secure the adherence of the other provinces, but emissaries were later sent asking their coöperation. Troops were afterwards sent, and a number of encounters occurred. Both sides killed their prisoners as a general rule, and the combats were very sanguinary.

Manuel Belgrano was a native of Buenos Aires. He had been educated in Spain and had there imbibed republican ideas. His enthusiasm, his radicalism and his ability soon placed him at the head of the revolutionary forces. Though lacking in military training he proved himself an able general. He led an unsuccessful expedition into Paraguay, whither he went to induce the Paraguayans to join in the revolt. Another great defeat had been given the Argentine forces in Bolivia. Montevideo was evacuated, and the situation was becoming desperate. Belgrano was then placed in command and gathered together the scattered forces at Tucuman. The result was a decisive victory for the patriots. The gaucho cavalry followed the fleeing Spaniards clear to the boundaries of Bolivia, and inflicted great losses upon them. Belgrano foolishly followed up this real victory by another invasion of Bolivia, and met with an overwhelming defeat at Vilapugio, and again at Ayohuma. With the remnant of his army he returned to Argentine territory, and was succeeded in command by San Martin, who proved to be the real genius of the struggle for independence.

José de San Martin first saw the light on the 25th of February, 1778, in a little town on the Uruguay River, his father being an officer in the Spanish army. While still a small boy he was taken to Spain to be educated. Entering a military school, for his father had destined him for a military career, he finished that course, and at an early age enlisted in the army. He served in the many wars of that country against Napoleon, and rose to the rank of lieutenant-colonel. He also fought for a time under the great English general, Wellington, in his campaign in the Iberian peninsula. In these conflicts San Martin had imbibed liberal principles, and a hatred of all forms of oppression and injustice filled his soul. The success of the American republic inspired him as well as others, so that he joined with many in a secret society, pledged to the work of establishing a republic in Spain.

Man proposes, but God disposes. The struggle for independence in Argentina appealed to this patriot and he decided to return to his native land. He arrived at an opportune time, for the successes of the Spanish troops had plunged the patriots into despair. In March, 1812, San Martin landed in Buenos Aires. His first step was to organize and drill some effective regiments of infantry in that city, for men trained in military tactics were wanting. He selected the finest physical and moral specimens of manhood that could be found, and subjected them to a rigid discipline. The lazy and cowardly ones were weeded out, until he had only a small force, but this body was composed of real soldiers. With these men he gained some victories, but success did not seem possible to him along these lines. He therefore planned a new move with all the genius of a great commander, who cares not for temporary success but sees only ultimate victory.

To San Martin the only hopeful plan seemed to be to drive the Spaniards out of Chile, and then attack Peru, the stronghold of Spanish power in South America. He aimed not only for the independence of Argentina, but of all of that great continent; he vowed he would not be satisfied until the last Spanish soldier had left the soil of South America, and every province was free. To this end he sought the appointment as governor of Cuyo, nestling up against the Andes on the direct route to Chile, and now known as the province of Mendoza, in Argentina. The inhabitants of that section, who breathed the free air of the mountains, were notoriously anti-Spanish, brave and enduring. Chilean patriots who had been exiled were numerous here, too, and it offered good recruiting ground. He brought with him as a nucleus a part of the troops he had drilled in Buenos Aires, and the government later sent him a corps of negro slaves, who had been freed from bondage. For three years San Martin laboured steadily building up a great war machine. Though civil war waged in and around the capital he kept aloof from all these disturbances, and busied himself in recruiting, drilling and instructing officers, as well as men, raising taxes, gathering provisions, making powder, casting guns, building portable bridges and making all arrangements for transport and commissariat on his contemplated march into Chile.