Students in the United States caught up in the campus protests against the Vietnam War are going to re-stage graduation ceremonies cancelled in 1970.
Fearing violence on campuses, some US universities shut early that summer and cancelled leaving ceremonies.
Forty years later, students who missed out are now returning to hold the events that were cancelled.
Boston University says students in 1970 missed an "important milestone".
It will mean that former students, who are now grandparents in their sixties, will be able take part in the rites of passage that were interrupted 40 years ago.
"What memories, I remember getting my diploma in the mail, the world was upside down then," says an entry on Facebook about the returning students at Boston University.
At other universities, there is talk of "closure" for the "class that never graduated".
In 1970, the symbolic end-of-term events for students leaving universities were overtaken by political protests about the Vietnam War.
In May 1970, the shooting dead of four student protestors at Kent State University in Ohio by national guardsmen sparked a wave of campus disruption.
Many universities shut down, cancelling the end of term speeches, photographs and the caps and gowns of graduation ceremonies.
There were occupations, sit-ins, protest concerts and stand-offs with the authorities, and fearing violence, many universities cleared their campuses.
Boston University was one of the campuses that closed in the summer of 1970, in what it described as a time of "national turmoil".
It meant cancelling the "commencement" ceremonies for those leaving university that summer.
Now it is asking back the Class of 1970 for a weekend of events to be held later this month.
They will join the current year group of students leaving the university this summer.
However there will also be a remembrance for more than 150 students from the university's class of 1970 who have since died.
The University of Cincinnati is also holding events for the students who missed out on leaving events in 1970.
An event this summer is intended to give these students an "opportunity to symbolically reclaim their lost commencement".
The university says it will give the students of 1970 the chance "to finally walk across the stage to well deserved applause".