«Sesame Street» co-creator Lloyd Morrisett has died, Sesame Workshop announced Monday. He was 93 years old.

«As an honorary lifetime trustee, Lloyd leaves a huge and indelible legacy among generations of children around the world, with ‘Sesame Street’ just the most visible tribute to a lifetime of good work and lasting impact,» Sesame Workshop (originally known as Children’s Television Workshop) wrote from one of its founders.

Morrisett co-founded the Children’s Television Workshop with close friend and fellow «Sesame Street» creator Joan Ganz Cooney in 1968, where he continued to serve as chairman of the workshop’s board until 2000. He remained a board member until his death.

Spurred in part by the Civil Rights Movement and the war on poverty, the duo set out to create a television series that would give underprivileged children the opportunity to prepare for school. Therefore, they created “Sesame Street” in 1969. After spawning the famous children’s series, the Children’s Television Workshop was renamed Sesame Workshop.

“Without Lloyd Morrisett, ‘Sesame Street’ would not exist. It was he who first came up with the idea 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 greatly missed.» saying Ganz Cooney on his passing.

In addition, Morrisett also served as president of the John and Mary R. Markle Foundation from 1969 to 1998, during which time he launched the foundation’s program in information and communications technology. Before joining the Markle Foundation, she served as vice president of the Carnegie Corporation of New York and the Carnegie Foundation for the Advancement of Teaching.

Born in 1929 in Oklahoma City, Morrisett received his bachelor’s degree from Oberlin College. He later became a trustee of the university and was named president of the board from 1975 to 1981. He later graduated with a degree in psychology from the University of California, Los Angeles and earned his Ph.D. in Experimental Psychology at Yale University.