When did Argentina become a country? Argentina officially became an independent nation in 1816. Of course, Argentina existed long before it became an independent country. The history of the country, and the gradual development of the nation’s identity, is both interesting and complex.

There are actually a few answers to when Argentina became a country:
After the European discovery of the Americas, Buenos Aires gradually became a port city, smaller and with less traffic than other surrounding port cities. Over the years, Buenos Aires became a central location for porting of illegal goods more than anything, considering the fact that the city did grow in size but there was not enough traffic to sustain (legal) jobs for all of its citizens.
In 1806, Great Britain began to invade the Americas, and they took possession of Buenos Aires. A back-and-forth sparring took place between British forces and local ones, eventually ending with the freedom of Buenos Aires/Argentina in 1807.
This was most likely the event that really triggered a national identity for Argentina, and the point at which it began to develop as a country.
During the early 1900s, Argentina grew in population by leaps and bounds, inviting European immigrants of all nationalities to join their country. It was not until the time of the World Wars, the 1930s and 1940s, that Argentina began to see some conflict, but when they did, it was fairly intense.
Triggered by military invasions, financial crises, and other forms of upheaval, the country went through some civil war and some military coups; the main coup that took place brought a colonel named Juan Peron into power.
Peron ruled quickly and drastically: he brought major employment to the country by introducing fast, cheap technology, railroads, factories, and many more new industries. He also paid attention to the needs of the workers by bringing in minimum wages and other mandatory rights. Opinion on Peron and whether he was good or bad for Argentina is still quite divided. Along with all the improvements he made to the employment situation, he also threw the country into a cultural black hole by cutting off artistic importations from Europe altogether.
Several more years followed of presidential rule followed by military rule followed by another coup; modern Argentina is much the same, with the election of various presidents who operate with much the same degree of power as Peron did. The next step in Argentine history is difficult to predict; it seems that they’re still in the process of determining what system works best for managing their hard-won independence.