Note that you may need to use the term "mental retardation," especially for older materials
Encyclopedia of Special Education
Note that this is in the Reference section and Floor 2 and cannot be taken from the library.
See Volume 2: History of Special Education. Volume 3: Residential Facilities
Encyclopedia of American Disability History
Note that this is in the Reference section on Floor 2 and cannot be taken from the library.
See Volume 1: Down Syndrome
Children with Down's Syndrome
Chapter 2 gives a history of inclusion.
A History of Childhod & Disability
See Chapter 6: Mental Retardation, Educability, and Worth, pages 153-187
Outside the Mainstream
Chapters 5 & 6: The Feeble-Minded Child Before 1890; The Defective Child, 1888-1918, pages 107-152
Schooling Children With Down Syndrome
The first two chapters will be particularly relevant.