Okay kiddo, so imagine there are a bunch of countries in an area called the Southern Cone. These are places like Argentina, Uruguay, and Chile.
Now in the early 1900s, some people in those countries started to feel very proud of their country. They wanted to show everyone how great it was and how much they loved it. They formed groups called patriotic leagues.
These leagues would organize big events like parades and speeches to celebrate their country. They would also sometimes do things like raise money for important causes or help out in their community.
But here's the thing, some of these patriotic leagues started to get really extreme in their thinking. They believed that their country was the best and that anyone who didn't agree with them was wrong. They might even use violence to try and force their ideas onto others.
So while some patriotic leagues were just groups of people who loved their country, others became pretty dangerous.