Before the Education for All Handicapped Children Act was signed into law on Nov. 29, 1975, many public schools could turn away students with disabilities whom they deemed too challenging to educate.

To mark 50 years of this landmark law — which would in 1990 become known as the Individuals with Disabilities Education Act — we’re taking a look at the law’s educational impact and what its future holds in the two-part series collected below.

In part one, we examine how IDEA sparked innovative learning approaches and technologies that benefit students both with and without disabilities. And in part two, we explore how persistent teacher shortages in the special education field are hindering student progress, as well as the promising recruitment and retention practices that are emerging.