United States of the Southern Cone/Estados Unidos del Cono Sur

I recently came across a thread that discusses an alternate Argentina that doesn't fall victim to post-independence political instability and civil wars the way OTL Argentina did. The thread - along with an accompanying map/chart - can be found at the following link: https://www.reddit.com/r/worldbuilding/comments/grd5k0
According to its creator, its premise is that
it did not fall prey to the unstable political conditions that most of Latin America dealt with, leading to it competing with America [i.e. the United States] for dominance of the New World. For that reason, it drew many more immigrants from Ireland during the Great Famine than real Argentina did, and it was able to establish a colonial presence in the Asia-Pacific [i.e. the Philippines].

I'm trying to pinpoint an exact POD, but based on the above, my sense is that it would be quite early, at or just after independence in the 1810s but before civil war starts to break out ca. 1820. Would any of you know the exact POD?
Argentina lacks coal, iron and other resources necessary for early industrialization. However you can find these resources in La Plata Basin (coal in the South of Brazil and Iron in Bolivia. The Viceroyalty of La Plata had around 2 million people in OTL so disputing theses resources against the stronger Brazilian monarchy would be hard.