War of Independence

During the following decade a war for independence ensued in the former Viceroyalty, its regions divided between patriots and royalists.

While the cities of present-day Argentina would align with the independents after 1811, the other regions would follow differing paths:

• Paraguay seceded, declaring its independence from Spain 1811 and from Argentina in 1842.
• Upper Peru was disputed with the royalists from Peru until it declared independence as Bolivia in 1824.
• The eastern bank of the Uruguay river was invaded by the Brazilian-Portuguese Empire in 1817 and declared independence as Uruguay in 1828 after the Argentina-Brazil War.

Internal conflicts would cause political instability within the patriots. In just four years the Primera Junta was replaced by the Junta Grande, the first and second triumvirates, and the first Supreme Director. In 1813 an Assembly convened to declare independence but it could not do so due to political disputes. A Civil War ensued between the provinces joined into the Federal League and the Supreme Directorship.

By 1816 the United Provinces of South America were under severe internal and external threats. In July a new Congress declared independence and named Juan Martín de Pueyrredón as the Supreme Director. The military campaign became the responsibility of José de San Martín, who led an army across the Andes in 1817 and defeated the Chilean royalists.

With the Chilean navy at his disposal he then took the fight to the royalist stronghold of Lima. San Martín’s military campaigns complemented those of Simón Bolívar in Gran Colombia and led to the independent’s victory in the Spanish American wars of independence.

Argentine Civil War

The 1820 Battle of Cepeda, fought between the Centralists and the Federalists, resulted in the end of the centralized national authority and created a power vacuum. A new constitution was enacted in 1826, during the War with Brazil, when Bernardino Rivadavia was elected the first President of Argentina. This constitution was soon rejected by the provinces, due to its Centralist bias, and Rivadavia resigned shortly after.

The provinces then reorganized themselves as the Argentine Confederation, a loose confederation of provinces that lacked a common head of state. They would instead delegate some important powers to the governor of Buenos Aires Province, such as debt payment or the management of international relations.

Governor Juan Manuel de Rosas ruled from 1829 to 1832, and from 1835 to 1852. During his first term he convened the Pacto Federal and defeated the Unitarian League. After 1835 he was given the “Sum of public power”. He faced unitarian resistance and a constant state of war, including a French blockade from 1838 to 1840, the War of the Confederation in the north, an Anglo-French blockade from 1845 to 1850, and the Corrientes Province revolt.

Rosas remained undefeated during this series of conflicts and prevented further loss of national territory. His refusal to enact a national constitution, pursuant to the Pacto Federal, led to Entre Ríos Province Governor Justo José de Urquiza’s reclaiming provincial sovereignty. He defeated Rosas at the Battle of Caseros, forcing him into exile. The San Nicolás Agreement followed and in 1853 the Constitution of Argentina was promulgated.

Emergence of Modern Argentina

Following the secession of the State of Buenos Aires from the Confederation, and its later return, Bartolomé Mitre was elected the first president of the unified country in 1862. National unity was further advanced by the War of the Triple Alliance, which left over 300,000 dead and devastated Paraguay.

After 1875 a wave of foreign investment and immigration from Europe led to the strengthening of a cohesive state, the development of modern agriculture and to a near-reinvention of Argentine society and economy. The rule of law was consolidated, in large measure, by Dalmacio Vélez Sársfield whose 1860 Commercial Code and 1869 Civil Code laid the foundation for Argentina’s statutory laws.

General Julio Argentino Roca’s military campaign in the 1870s established Argentine dominance over the southern Pampas and Patagonia, subdued the remaining native peoples, and left 1,300 indigenous dead. Waged to suppress Malón raids, some contemporary sources indicate that the “Conquest of the Desert” was a campaign of genocide by the Argentine government.