Developments in the early 1960s not only focused on the integration of students with disabilities into the public system. Leaders in the field of special education also advocated for the development of a range of special education placements so that at least some students would be integrated into public schools and classrooms.

The early 1960s also saw the introduction of a continuum of placements ranging from least restrictive to most restrictive was introduced (Reynolds, 1962). In 1970, the continuum (placements along straight line) was described as a cascade (an inverted pyramid) (Deno, 1970). In the cascade, the least restrictive setting was at the top and broadest part of the pyramid indicating more students would be placed in the least restrictive environments. The most restrictive settings were at the bottom and narrowest point of the pyramid, indicating the fewest students would be placed there. The principle of least restrictive environment was included in court rulings in the late 1960s and early 1970s.


Two boys in a classroom