Abstract: | Does immigration hamper union organizing in the United States? The prevailing literature strongly suggests that it does and for two reasons: first, immigrants increase the labor pool and diminish union influence over the labor market. And second, immigrants may be harder to organize than native workers. In this dominant view, unions are well served to restrict immigration and have always done so. But how, then, to explain the fact that American labor has long been deeply divided over the response to immigration? Drawing on new archival research and interviews, this paper uncovers a neglected side of American labor history in which many union leaders have extended solidarity to immigrants and sought to organize them. Moreover, analysis of time series data on immigration and union density corroborates the implicit theory of this alternate account of labor history: immigration has, in fact, no statistically significant effect – either positive or negative – on union density over time. Depending on specific conditions and strategies, unions can and have been successful in organizing during periods of high immigration. |