when was the first person diagnosed with autism

The first person diagnosed with autism was Donald Gray Triplett. He was first examined by child psychiatrist Leo Kanner in October 1938, and in 1943, Kanner published a paper describing autism with Triplett referred to as "Case 1." This marked the formal recognition and diagnosis of autism as a distinct condition. Donald Triplett's diagnosis initiated decades of research into autism spectrum disorder. He lived from September 8, 1933, to June 15, 2023, and his case remains foundational in autism studies.