She has played the character of Susan Robinson on Sesame Street since its debut in 1969.
Long earned her Ph.D.
in urban education in 1973 from the University of Massachusetts Amherst while she was starring on Sesame Street.
She has acted in musicals (such as Guys and Dolls) and appeared on the Flip Wilson Show with other Sesame Street cast members during its first season.
As of October 2018, Long's character, Susan, is one of only two remaining characters who are still played by the actors who originated the roles.
(The other is Bob (Bob McGrath).) In the early years, she voiced a few female Muppet voices including Roosevelt Franklin's mother Suzetta and other Muppets where a female voice was needed.
In addition to starring on Sesame Street, Long is a consultant and public speaker on issues of multiculturalism and education.