Europeans that migrated to the Americas came here in search of wealth. They ended up almost putting the Native American into extinction. They also enslaved them, tricked them, and forced them to live on reservations. They celebrated this with a holiday we now call Thanksgiving.
The Africans did not choose to migrate to the Americas. They were brought here on slave ships with disgusting conditions. Many of them died along the way. Africans were forced into slavery for hundreds of years. When slavery was abolished Blacks still endured hardships for many many years, even until now.
For the most part, Europeans, Africans, and Native Americans have pretty civilized relations today.
The Columbian Exchange brought lot of new animal species from the Old World to the New World, and lot of plants from the New World to the Old World, both of which had huge impacts.
The animals brought from the Old World to the New World, like the cows, horses, goats, sheep, poultry, all had big impact. Some were excellent for working on the farmlands, all of them were producing large amounts of excrement which was great for fertilization of the soil. Some were great for quick traveling, as well as being very useful in warfare. The majority of them provided food, be it meat, milk, or eggs, while some provided wool for clothing.
The plants brought from the New World to the Old World had huge positive impact in Eurasia as they managed to provide lot of food for the people, thus largely preventing malnutrition and famine. The most important of these plants is probably the potato, which has become one of the most valuable food sources, and one of the most popular as well.
Normally, Communism is associated with the equal distribution of wealth and the common ownership of businesses.<span />
Strict application of widely publicized laws, management techniques, and etc