Who brought new domestic animals new food plants and new diseases to the Western Hemisphere?

The Europeans traders and settlers who traveled to the Americas, especially the Spanish, French, and English.

In 1492, Columbus made his famous voyage to the Americas. "The Encounter" is the term used to describe the ensuing relations between these European explorers, mostly from Spain, France, and later Britain, and the native peoples (the Native Americans, or "Indians") The trade following trade between the Europeans and the Native Americans introduced new goods to both areas; the Europeans brought domestic animals such as horses and pigs, plants such as sugar cane, and diseases such as small pox and measles to the Americas. The Americas are within the Western Hemisphere. The disease syphilis and crops such as potatoes, corn (maize), and tomatoes also made their way from the "New World" to Europe.