What was the first parent group that organized for children with disabilities?

While there were smaller, local groups advocating for children with disabilities before, the first nationally organized parent group for children with disabilities is considered to be the National Society for Crippled Children (now Easterseals).

It was founded in 1921, initially focused on polio, but quickly expanded to encompass all types of disabilities.

It's important to note that the term "crippled" is now considered outdated and offensive. However, it's essential to understand the historical context of the organization's name and recognize its significant role in advocating for the rights and needs of children with disabilities.