Why do the immigrants go to the cities rather than to the country districts? The chief reason is that most immigrants come to the United States to find work, and work is most easily found in the large cities. The great majority of immigrants have learned no trade before they come to America, hence they must seek jobs which require no great amount of skill or training. Another reason is that the immigrants want to be near others who speak their own language. In every large city these foreign colonies or settlements are created—Italian, Polish, Jewish, and so on. The newcomer naturally prefers to live in one of these colonies until he learns the English language, but having become accustomed to the city he rarely leaves it. Among the many millions of immigrants who have come to America during the past fifty years the great majority have gone to the cities, particularly to the large cities. New York City, for example, contains today more than two million people who were not born in this country. Nevertheless, the cities have not been built up by the immigrant alone. Large numbers of native Americans have left the rural districts and have helped to swell the population of the urban centers. =The Ebb and Flow of Immigration.=—The United States has been the melting-pot of the nations. No other country has ever welcomed to its shores so many millions of people from all parts of the earth. One hundred years ago there were relatively few foreign-born persons in the country. But waves of immigration soon began to come and the number of incoming aliens, which was less than ten thousand in 1790, rose to more than four hundred thousand in some of the years preceding the Civil War. The immigrants during this period were for the most part from England, Ireland, and Germany. During the Civil War the influx subsided, but when the war was over it quickly began to swell once more and it continued, with various ups and downs, to the outbreak of the World War in 1914. [Sidenote: Where the immigrants have come from.] In some years, during this period since 1865 the number of immigrants has been as low as 200,000; in other years it has run above a million. Nearly every European race has been represented in this influx, although some have come in much larger numbers than others. Down to about 1880 most of the newcomers were from Ireland, England, Scotland, Germany, the Scandinavian countries, and the other regions of Northern Europe. But since that date the source of immigration has been steadily shifting. During the past forty years a much larger proportion has been coming from Italy, Austria, Hungary, Poland, Greece, and some of the smaller countries.[11] This has brought in many millions of people who are not of Celtic or Teutonic stock. [Sidenote: Effects of the war on immigration.]