At the end of the 19th century, there was a large influx of immigration from Central and Eastern Europe, which resulted in a bipolarization of Belgian Jewry. (WebCorp)
However, World War II sparked an influx of immigration, and by 1960 the population stood at 15,957. As well, the ethno-cultural composition of the area began to change with the advent of groups such as the Italians, Jews and Eastern Europeans to name but a few.(WebCorp)
As the political conditions in California were favorable to the American interests during the opening months of Polk's administration, so also was the influx of immigration from across the mountains. (WebCorp)