(iv.) The Act also provided that after July 1, 1927, the total number of immigrants in any one year was to be reduced to a total of 150,00o, the quota of each nationality being the proportion of 150,00o determined by the ratio between the number of in habitants having that national origin to the total population of the United States in 1920. This is known as the "national origin" plan. It did not take effect on July 1, 1927 Congress postponing its operation for a year. On this basis, according to proposals laid before Congress in March 1928, the principal alterations would be the increase of the quota of Great Britain from 34,007 to 66,000, and the reduction of the quota of Germany from 51,227 to 25,00o, of the Irish Free State from 28,567 to 17,500 and of Norway, Sweden and Denmark from 18,803 to it,o0o.
The national origin plan was intended to give immigrants from the various countries representation approximately proportional to the number of people of their own nationality domiciled in the United States. In principle it seemed fairly easy to work out such representation; in practice it has proved difficult and the provisional quotas to be allotted have been changed several times.
The restrictive legislation was two-fold in its intention: (i.) to reduce the number of immigrants so as to afford an opportunity for assimilation; (ii.) to allow future immigration on a scale designed to preserve a reasonable degree of homogeneity in the population of the United States. "The myth of the melting pot has been discredited. . . . The day of unalloyed welcome to all peoples, the day of indiscriminate acceptance of all races has definitely ended" (Johnson).
The effect on the proportion of the English-speaking races (English, Irish, Scotch and Welsh) entering the United States is shown in the following table:— Immigration Into the United Slates of English and Non-English Speaking Races The total immigration from south and eastern Europe was reduced to less than one-fifth of that from northern and western Europe, the proportion being 15% and 84% respectively. The
effect is still more noticeable if the emigration to the United States from the most important European countries of emigration in is compared with that during the years 1921-7:— (ii.) Certain classes of immigrants are exempted from the quota arrangements, e.g., the dependants of previous immigrants naturalized in the United States, and certain other individual The policy of restriction has been based mainly on considera tions of race-dilution, literacy, standards of living, etc. It re mains to be seen what will be the economic effect of the closing of the main source of the unskilled labour supply of the United States. Unskilled labour in the past has been drawn mainly from the new immigrants and the supply of skilled labour largely from their children, since the tendency is for the more laborious and less remunerative tasks to be left to immigrants. The immi grants under the quota law are not likely to be of the type which will fill the places in the industrial system left vacant by the old type of immigrant. One effect of the restriction on overseas immigration is already apparent; it has encouraged the movement of negroes from the agricultural southern States to the industrial North and it is drawing from across the Mexican border immi grants who are presumably no more desirable from a biological point of view than those European races excluded by the quota law. It has also led to increased immigration from Canada, from which country and from Mexico there is in addition a considerable amount of illegal immigration. The extension of the quota ar rangement to countries on the American continent and an aliens registration law have been advocated. For the National Origins Act of 1929, see UNITED STATES, Population and Social Conditions.