American immigration history can be viewed in four epochs: the colonial period, the mid-nineteenth century, the turn of the twentieth, and post-1965. Each epoch brought distinct national groups, races, and ethnicities to the United States.
The immigrants contribute to the development of the country they go to, because they go looking for work, and they usually work harder that they would if they were in their own country.
In that sense, immigration benefits one country because it gains labor, that is necessary to raise one economically stable country.
When one country has a stable and strong economy, the population become happy, and it leads to one stable society as well; that attracts more immigrants, so we can conclude that immigration leads to more immigration and that its important to any country.
