>>520184874 (OP)
Since colonization Latin America was run in a feudal manner with European noblemen owning all the farmable land serving under the King of Spain, brown workers serving as peasants and European non-noblemen serving as merchants and other semi-educated manual labor.
Independence changed little about this, especially in Brazil because the nobility kept running the country and most browns were African. Our countries simply started abolishing nobility privileges and brown segregation little by little, but you still had a 90% brown population working as farmhands growing cashcrops in exchange for a portion of land where they could farm. This was known as the Hacienda/Facenda system.
What changed things was the Green Revolution. Basically around the 40s-60s modern farm equipment, artificial sweeteners, artificial fertilizer, artificial textiles and artificial tinctures, killed 90% of Latin America's cashcrops, reduced the price of food by around 75% and made 90% of farmhands unnecessary. This killed the Hacienda/Facenda system and made it so 80% of the population migrate from the country side to the cities in a couple of decades.
City municipalities were not only overwhelmed,but also the rich elites did not give a shit about the browns moving in and our governments lost most of their revenue due to the collapse of the rural areas, and the abandoned rural areas became breeding grounds for drug cultivation and communist movements, so the new migrants just settled ilegally around the cities and in a few years the cities grew 5-10 times their og population.
These settlements were technically not cities,so they did not have police service, electricity, water, sewage, etc. so they were breeding grounds for gangs and drug lords.
Brazil had it worst than most because sugarcane farming was particularly labor intensive until it wasnt.