In colonial America, Africans "contributed" to society by being a source of income for people who bought and sold them into slavery. They also contributed by being laborers in the southern plantations.
Women contributed to the society by being a house wives --meaning they took care of the house-- as well as cooking meals for the family and taking care of the children.
Native Americans, in the earlier days, contributed by trading with settlers and teaching them how to do things in their environment.
(Sorry I really don't know what the children did)
The Great Migration is depicted in the image. Also known as the Great Northward Migration, it marked the movement of 6 million african americans from the rural south of the United States to the Northwest, Midwest and West, that took place between 1916 and 1970. It was one of the most rapid internal migrations in the world not caused by war or famine, and it meant leaving their economic and social base to find a new one, made easier by the labor shortage that WWI had generated.
The Soviets were proclaiming themselves as communist, though the reality was not as the communism truly says a state should be run. If the Soviets practiced the textbook communism, then everyone in the society would have been equal. Everyone was going to earn the same amount of money and get the same things necessary for life without any problem. The economy would have been self-sustaining and that was going to be supported by excellent planning. There were not going to be social classes, but everyone would have been in the same class. The Soviets did pretty much everything wrong with those ideas, and in all fairness the human nature just doesn't allow for something like that to exist.
Mikhail Gorbachev was hated by the hardline communist. The main reason for that was that he was trying to make the country slightly more liberal, more open to the world and to modernization. That was seen as treason of the communist ideology by the hardline communist so they were against all of that.
Knossos, Assur, Sumer, west through the Libyan desert.
