Given Germany as it then was, and particularly because of its geographical position, Prussia was a receptacle for Jewish immigration from the east to the west. From the beginning of the twentieth century, the big cities were the gathering place of Eastern Jews in Prussia. Until the beginning of the World War, this stream could be kept somewhat within bounds, but the war swept aside all protective barriers in this regard. One can even say that social democracy used its political power to give a major boost to Eastern Jewish immigration and naturalization.
As we have already noted, there was a growth in the total Jewish population of Prussia between 1 December 1910 and 16 June 1925 from 366,876 to 403.969, or 10.1%. The entire population of Prussia over the same period and on the same territory rose about 3,119,000, or 8.9%, substantially less than the rise in the Jewish population. This was despite the loss of territories with significant Jewish populations, despite the surplus of deaths over births, despite baptisms and those who gave up their religion altogether!
A closer look at the statistics and facts gives an entirely different picture of the Jews since 1910. Between 1911 and 1924, there was an excess of deaths over births of 18,252. Subtracting that number from the 366,876 Jews in 1910 results in a figure of 348,624. Then there were 15,408 Jews (14 times 3 per 1,000 = 4.2% of Jews) who between 1911 and 1924 converted or left their faith altogether. That would leave us with 333,212 Jews in 1924. However, the actual number of believing Jews in 1925 was 403,969. This must be the result of the immigration or migration of Jews from the lost territories, a total of around 70,000.
In reality, this flood of Jews must be considerably higher than 70,000., since many of those 70,000 were already dissidents, Catholics or Protestants, or did not reveal their religion.
Of the 403.969 Jews in Prussia on 16 June 1925, 68,114 were foreigners, 7,364 had no nationality, and 909 were of unknown citizenship. It seems to us of considerable political significance to know the nationality of these 68,114 Jewish foreigners.
Poland takes the lead. 35,385 of these Jewish foreigners came from there. Of the 35,585 Polish Jews, nearly half — 17,423 — lived in Berlin.
9,498, or 2.35%, came from Austria.
In third place among the Jewish foreigners is Soviet Russia, with 6,986, 5,185 of whom lived in Berlin. These 6,986 Russian Jews are 1.73% of all Jewry in Prussia.
Czechoslovakia provided 95,263 total immigrants, or 0.25%, putting it in second place, but its 3,574 Jews, or 0.89%, put it in fourth place with regards to Jewish immigrants.
Other nations included Hungary with 2,480 Jews, Romania with 2,156, the Netherlands with 1,791, and Lithuania with 1,350 Jews.