The facts of governmental pressure amounting to an expulsive force, and reflected in an extraordinary rate of immigration, in a movement of families unsurpassed in the American immigration, the largest part economically dependent, in an occupational grouping of skilled artisans, able to earn their livelihood under normal conditions, and in a permanence of settlement in this country incomparable in degree and indicating that practically all who come stay--all these facts lead irresistibly to the conclusion that in the Jewish movement we are dealing, not with an immigration, but with a migration. What we are witnessing to-day and for these thirty years, is a Jewish migration of a kind and degree almost without a parallel in the history of the Jewish people. When speaking of the beginnings of Russian Jewish immigration to Philadelphia, David Sulzberger said: "In thirty years the movement of Jews from Russia to the United States has almost reached the dignity of the migration of a people," he used no literary phrase. In view of the facts that have developed, this statement is true without any qualification. This migration-process explains the remarkable growth of the Jewish population in the United States, within a relatively short period of time. In this transplantation, the spirit of social solidarity and communal responsibility prevalent among the Jews has played a vital part. The family rather than the individual thus becomes the unit for the social life of the Jewish immigrant population in the United States. In this respect the latter approaches more nearly the native American population than does the foreign white or immigrant population. One of the greatest evils incident to and characteristic of the general immigration to this country is thereby minimized. Again, the concentration of the Jewish immigrants in certain trades explains in great measure the peculiarities of the occupational and the urban distribution of the Jews in the United States. The development of the garment trades through Jewish agencies is largely explained by the recruiting of the material for this development through these laborers. These primary characteristics of the Jewish immigration of the last thirty years will serve to explain some of the most important phases of the economic and social life of the Jews in the United States, three-fourths of whom are immigrants of this period.