From 1968 to 1970, he briefly served as provost and acting president of Lincoln University.
[1] In 1981, Harleston was selected as president of City College of New York, beating out finalists Shirley Chisholm and Homer Neal.
[2] During his administration of the college, the policy of open admissions resulted in its status as having an engineering school with the largest number of black and Hispanic students.
The school was also disrupted by student takeovers of facilities in 1989 and 1991, an incident where nine students were crushed to death in the gymnasium stairwell outside a celebrity basketball game, and racially divisive statements issued by professors Leonard Jeffries against white people and Michael Levin against black people, homosexuals and feminists.
Amid the uproar of such controversies, Harleston resigned, seeking a more tranquil campus scene.