The Columbian Exchange
Tomatoes were transferred from the "old world" to the "new world". These, along with many other items, were traded. We use tomatoes almost everyday, and they came from the "old world". We may use them for pizza, spagetti, and many other foods.
We got turkey from the "new world" as well. We use turkey for food and special dinners like Thanksgiving or Christmas.
We also use corns for food and snacks like popcorn, or just corn on the cob.
Livestock came from the "old world" and we still use it today for food and farms.
We use peanuts for snacks and foods also. This came from the "new world". All these foods that we have now might not be here if the Columbian Exchange never happened. We would have never been introduced to all these new foods and goods.
Smallpox and other disease also came from the "old world". Smallpox is a sickness that the Native Americans and Africans were not immuned to. So they could possibly die from this disease.