Peru
Argentina
Argentina was a minor Spanish colony. All it had was agricultural and animals. Mexico and Peru were far more important places - because of their silver. By the second half of the 19th century, Europe is getting quite rich. And the wealth produces a surge in demand for food. Simultaneously technological developments make several things possible. Railways help move goods from inland to the ports. Steamships make long-distance ocean trade much more viable. And refrigeration makes it possible to ship fresh meat to Europe (instead of having to dry and pickle it first). All these factors combine to turn Argentina into a massive exporter, and Buenos Aires as the gateway. A large number of migrants arrive in Argentina. To trade. To farm. To work. This is followed by capital. Capital chasing returns helps build the railways, the factories, the ports. And banking. Utilities. The works. Argentina booms. And becomes the world's richest country per capita.
The country becomes rich, but depends on agricultural exports and foreign capital. This works well until 1914 and the first world war. Trade is disrupted. Capital markets are disrupted. And the European demand for imports declines. The Great Depression lands the final blow. Global commodity markets collapse. Argentina slips into a relative decline.