How might history have been different if the cultures of Europe and the Americas had never come into contact

Before the arrival of the Europeans to America, there were advanced civilizations in America, therefore, without the Europeans, I think these civilizations would have continued to develop, mainly the Aztec and Inca civilizations. Also, other civilizations would have grown. And a political-economic system similar to feudalism may have developed.

The population in America would also be larger and more interconnected. Also, the civilizations would have been developed more scientifically.

Europe, meanwhile, would have faced an economic crisis. Before the conquest of America, Europe was experiencing a great recession. Quite possibly this recession would have deepened.

Also, they would have faced a great famine; due to the exchange of products between America and Europe, the Europeans had more food options, for example, the potato.

Likewise, if Europeans had not reached America, other parts of the world would possibly have another history as well, such as Africa and Oceania, and even Asia.

I hope this information can help you.