Examining 100 years of history, and fusing sociology, urban planning and criminology with literary and cultural studies, this chronicles how and why marginalized populations - immigrant Americans in the Lower East Side, gays and lesbians in Greenwich Village, the black underclass in Harlem and Chicago, and the new urban poor dispersed across American cities - have been selectively targeted as 'urban underworlds' and their neighbourhoods characterized as miasmas of disease and moral ruin.