Why South American countries (Brazil) are not as strong as North American countries (the United States)?

Because people in North America have moved here from Europe, especially Britain, they may know more about new technologies, new ideas and new cultures before they leave, and some people living in North America are more "developed". To put it bluntly, the British were the most powerful national power in the world at that time, so they had great power and strong technology, and all this knowledge was spread to the United States. At that time, people in North America will have more extensive contact and development with Europe and introduce new technologies.

On the contrary, South America, Brazil and other countries have not introduced science and technology, and most people have not moved from Europe, so culture and technology may fall behind. Moreover, in history, the people here were "suppressed" by European powers, but only used their resources without developing that country.

So, the difference today is that North America is rich and South America is backward. Even so, the countries in South America are very active and have developed very rapidly in economic and cultural aspects in recent years.