In 1492, Christopher Columbus' first voyage launched an era of large-scale contact between the Old and the New World that resulted in this ecological revolution; hence the name "Columbian" Exchange.
As an example, the plants that originated in the New World include:
avocado
beans
cashew
chia
chicle (chewing gum base)
chili pepper (includes the bell pepper)
cocoa / chocolate
cotton (long staple variety, 90% of modern cultivation)
maize (corn)
papaya
peanut
pecan
pineapple
potato
rubber
squash (incl. pumpkin)
sunflower
strawberry (American species used in modern hybrids)
sweet potato
tobacco
tomato
vanilla
The Columbian Exchange has been one of the most significant events in the history of world ecology, agriculture, and culture, says Wikipedia.
One example from the New World:
Christopher Columbus was one of the first Europeans to encounter chili peppers - in the Caribbean, He called them "peppers" because of their similarity in taste (though not in appearance) with the Old World peppers of the Piper genus.
Chilies were cultivated around the globe after Columbus' time.[4][5] Diego Álvarez Chanca, a physician on Columbus' second voyage to the West Indies in 1493, brought the first chili peppers to Spain, and first wrote about their medicinal effects in 1494.
From Mexico, at the time the Spanish colony that controlled commerce with Asia, chili peppers spread rapidly into the Philippines and then to India, China, Korea and Japan with the aid of European sailors.