(WTNH) — Sesame Street officials announced on Monday that its co-founder and beloved friend, Lloyd N. Morrisett, died at age 93.

Morrisett was an experimental psychologist with a career in education, communications, and philanthropy. He co-founded the Children’s Television Workshop (now the Sesame Workshop) in 1968. The organization went on to create the iconic children’s television series Sesame Street, which was the first and most well-known series it made.

Colleagues said that Morrisett was a revolutionary thinker, and credit him with the innovation of Sesame Street and its ability to educate young children.

On Twitter, the Sesame Workshop tweeted, “Joan Ganz Cooney, his co-founder and close friend, put it best. ‘Without Lloyd Morrisett, there would be no Sesame Street. It was he who first came up with the notion of using television to teach preschoolers basic skills, such as letters and numbers […] He was a trusted partner and loyal friend to me for over fifty years, and he will be sorely missed.'”

Morrisett served as the Workshop’s chairman of the board of trustees for more than 30 years before becoming a Lifetime Honorary Trustee, according to the Workshop.

Today his legacy lives on in Sesame Street, which continues after 53 seasons to bridge cultural and educational gaps for children across the country.