It is thought that the first humans lived in East Africa. Gradually they moved away from this starting point until they lived in all continents except Antarctica. So, in this sense, we are all the result of people moving permanently to somewhere else. We call that movement migration. People who leave are called emigrants. People who arrive are called immigrants.
People used to be able to move from one place to another readily because the world had far fewer people. For example, the people who left (migrated) from Asia about 14,000 years ago and crossed into what we now call America, where the first people ever to live there. And there were just a few thousand of them to begin with, so wherever they went the land had no people in it. Different groups of these people lived in different areas, and gradually their populations grew, and some moved on until all of the Americas had people.
Once an area has people in it, they think of that land as theirs. So anyone else coming to it may add pressure to the land, making it harder for those already there to survive. This is especially true if large numbers of people migrate quickly, so that they make an obvious difference to the area they are going to.
When people left Europe and sailed to the Americas from the 15th century onwards, the land was already occupied by people (native Americans/American Indians). But the pressure of more and more Europeans arriving, and their superior power in battle, meant that the original people were pushed back from the lands that the new settlers wanted. All of the European peoples in the Americas are migrants.
More migrants from this time were forced migrants. They were slaves from Africa.
When people move from one area to another, the new area is strange to them, so they often live together for support. They may not know the customs and the language. If there is no land available for them, then they must get jobs on other people's land or in other people's factories. They will get only the jobs that others don't want, so they will be among the poorest paid. This means that they can only afford to live in the poorest housing.
In a country like India, where millions migrate from their countryside villages to find work in the cities, this results in people living in self-made houses which we would call slums. The same is true in South America, where slums - called favelas - surround all major cities.
The people who are most affected by large scale migration are the poorest people in the place where the migrants move to, for they will be living next to migrants. So they tend to feel differently about migration from those who are better off and only come into contact with migrants as workers in their factories or perhaps as cleaners at home.
It takes time for people to become part of the place they move to. The migrants have to understand they are choosing to move to a place with different customs, and the best way to succeed is to take on most of those customs themselves and to speak the language of the place they are going to.
The people who migrate long distances often have a tough time. But their children are born in the country they migrate d to, and so they grow up in the new country. They find it easier to speak the same language, take on the same customs and so on. Gradually they become part of the society.
But it takes generations.
Generally people who migrate are the most enterprising. It takes a lot of effort to leave your home area and go somewhere else. So it is likely that these people will soon find a way of succeeding in the country they have migrated to. They will therefore be a benefit to the place they have arrived at. They may also be a benefit to those they have left back where they came from, for they may send back money to support them.
It doesn't happen quickly, and it happens more easily if migration is a slow process. It is likely to cause the most problems when it happens quickly.
The time when migration happens most quickly is when there is some disaster in the world and people are forced to move from the place where they would rather be. These people are refugees. The first refugees in America were the Pilgrim Fathers because they felt obliged to leave Europe as they held religious views that were not welcome in the country they left. Huge numbers of refugees moved from Russia and Germany in the late 1900s and into the 1930s. Refugees moved from Ireland and Italy in the 1800s. There are huge numbers of refugees in countries of the Middle East and Africa today.
The video below shows how farming people in Oklahoma and neighbouring parts of American were forced to migrate from the area where they farmed (which became known as the 'Dust Bowl') to California.
The difference between people wishing to move for a better life and those forced to move in fear of their lives is huge. Those willing to leave will be the brightest and most adventurous. Those forced to leave will be everyone, including many who find they cannot easily fit into where they have gone to. These are the people most likely to live in their own communities and try to keep themselves away from their new society. This is what makes them most noticeable in the place they have migrated to.
