"Throughout its lengthy history, few issues have caused the American labor movement more agony than immigration. It is ironic this should be the case as most adult immigrants directly enter the labor force. So eventually do most of their family members. But precisely because immigration affects the scale, geographical distribution, and skill composition of the labor force, it affects national, regional, and local labor market conditions. Hence, organized labor can never ignore immigration trends. Immigration has in the past and continues to affect the developmental course of American trade unionism. Labor's responses, in turn, have significantly influenced the actual public policies that have shaped the size and character of immigrant entries."
Available at: http://works.bepress.com/vernon_briggs/72/