On Jun. 17, 2023, the Mississippi man known as “Case 1,” the first person to be diagnosed with autism, died. Triplett worked for 65 years at the bank where his father Beamon Triplett was a primary shareholder.

Triplett’s autism diagnosis arose from a detailed 22-page letter sent to a Johns Hopkins researcher in Baltimore containing telling observations by his parents about his aptitudes and behavior. The letter remains a primary reference document for those who study the disorder.