Prior to the passage of the Education for All Handicapped Children Act in 1975 (PL 94-142), the educational experience of disabled children and youth was varied and uncertain. Many children and youth with sensory, physical or cognitive impairments received minimal skill development training in institutions, separate day classes, church basements or family homes (Winzer 1993). Although many states already required school districts to provide education to disabled students, PL 94-142 created a federal mandate that schools literally open those doors to students previously excluded from attending their neighborhood public schools. Functionally, PL 94-142 allowed them to walk through the front doors, past the regular education classrooms filled with nondisabled children, and straight into isolated classrooms down the hall. This article presents an evaluation of some of the demographic shifts in the composition of the segregated special education classroom, or what the author calls "the classroom down the hall," that have occurred in the three decades from 1975 through 2005. It examines the nature of the disabilities of the students educated there, the definitions and identification criteria applied across the decades and frames demographic differences seen within these classrooms in terms of the societal and educational constructions of disability operating during the period considered. Finally, the article presents support for the position that too many of America's children continue to spend too much of their day segregated in the classroom down the hall.