This study was prompted by the author's observation of a sharp dichotomy in interpretations written before and after the mid-1960s relying largely on the same data regarding the impact of Slavic immigrants on the Pennsylvania anthracite fields. Investigations dated between 1902 and 1964 blamed the Slavic immigrants for the exploitation of anthracite mines, the failure of unionization until 1902, and the relative social backwardness of Northeastern Pennsylvania. The old view led to the "split labor market" theory, which holds that immigrants tend to divide the labor market by their willingness to work for lower wages than those demanded by the established work force. Since 1964 historians such as Victor Greene and Harold Aurand have shown that Slavic immigrants in the anthracite fields were in fact a progressive social influence.Dr. Barendse starts with a hypothesis to explain the interpretive dichotomy: that social reality is a cultural construct created out of the perceptions and expectations of its creators, even when these are professional historians and social scientists. According to this hypothesis based on studies in the sociology of knowledge by Goffman, Berger, and Luckman pre-1964 experts expected Slavic immigrants to be poorly adapted to the social environment of the coal region and therefore perceived the behavior they studied as confirmation of that expectation. A very different picture emerges when the same source material is examined without such biases: the Slavic immigrants, despite alien languages and customs, made a remarkably fast adjustment in the 1890 1902 period, as attested to by their acquiring real estate, founding complex organizations such as the Polish National Church, demanding equal treatment on the job, and spearheading United Mine Workers organizing strikes. The monograph includes a brief history of the anthracite industry from 1740 to 1890 (when the Slavs arrived), a survey of immigration history, and an epilogue on the assimilation of Slavic-Americans into American society down to the present."