This document summarizes theories of marginalization and applies them to analyze homelessness in America. It defines the underclass as those furthest from social integration due to unemployment and poverty. The American Dream ideology equates social worth with employment and wealth, marginalizing the homeless. Theories discussed view marginalization as unwanted exclusion from social participation. The homeless experience both chronic (long-term due to disabilities) and short-term homelessness, but both subgroups are seen as the underclass. Marginalization results from an individual's incomplete participation in social norms and practices due to poverty and unemployment.