This chapter examines the treatment of immigrant workers through the lens of the Thirteenth Amendment. It examines how the intersection of labor and immigration laws impact immigrant workers in general, "guest workers" and undocumented immigrants. It argues that immigrant workers can be seen as a caste of nonwhite workers laboring beneath the floor for free labor in ways which violate the Thirteenth Amendment. Further, it suggests ways in which immigrant workers can use the Thirteenth Amendment to improve their situation and offers an analysis of how the Thirteenth Amendment can form a bridge for organizing between labor, civil rights, immigration rights and human rights groups. This chapter appears in The Promises of Liberty: The History and Contemporary Relevance of the Thirteenth Amendment (http://cup.columbia.edu/book/978-0-231-14144-4/the-promises-of-liberty), edited by Alexander Tsesis and published by Columbia University Press.