CAMBRIDGE, Mass. — Looking out over a sea of people in Harvard Yard last week, Mark Zuckerberg, Facebook’s chief executive and one of Harvard’s most famous dropouts, told this year’s graduating class that it was living in an unstable time, when the defining struggle was “against the forces of authoritarianism, isolationism and nationalism.”

Two days earlier, another end-of-year ceremony had taken place, just a short walk away on a field outside the law school library. It was Harvard’s first commencement for black graduate students, and many of the speakers talked about a different, more personal kind of struggle, the struggle to be black at Harvard.

“We have endured the constant questioning of our legitimacy and our capacity, and yet here we are,” Duwain Pinder, a master’s degree candidate in business and public policy, told the cheering crowd of several hundred people in a keynote speech.

From events once cobbled together on shoestring budgets and hidden in back rooms, alternative commencements like the one held at Harvard have become more mainstream, more openly embraced by universities and more common than ever before.

This spring, tiny Emory and Henry College in Virginia held its first “Inclusion and Diversity Year-End Ceremonies.” The University of Delaware joined a growing list of colleges with “Lavender” graduations for lesbian, gay, bisexual and transgender students. At Columbia, students who were the first in their families to graduate from college attended the inaugural “First-Generation Graduation,” with inspirational speeches, a procession and the awarding of torch pins.

Some of the ceremonies have also taken on a sharper edge, with speakers adding an activist overlay to the more traditional sentiments about proud families and bright futures.

After Columbia’s ceremony, Lizzette Delgadillo said she spoke about the pain of “impostor syndrome — feeling alone when it feels like everybody else on campus just knows what to do and you don’t,” and of how important it was to have the support of other first-generation students.

Ms. Delgadillo, who graduated with a bachelor’s degree in biomedical engineering, had lobbied for the event for three years, as a member of a group called the First-Generation Low-Income Partnership.

“The current political climate definitely pushed this initiative to come to fruition,” said Ms. Delgadillo, the daughter of Mexican immigrants living in Los Angeles.

Participants say the ceremonies are a way of celebrating their shared experience as a group, and not a rejection of official college graduations, which they also attend. Depending on one’s point of view, the ceremonies may also be reinforcing an image of the 21st-century campus as an incubator for identity politics.

“It’s not easy being a student, being a student anywhere, but especially at a place like Harvard,” Ward Connerly, president of the American Civil Rights Institute and a former University of California regent who campaigned against racial preference in admissions, said sympathetically.

But events like black commencements, he continued, serve only to “amplify” racial differences. “College is the place where we should be teaching and preaching the view that you’re an individual, and choose your associates to be based on other factors rather than skin color,” he said.

“Think about it,” Mr. Connerly added. “These kids went to Harvard, and they less than anyone in our society should worry about feeling welcome and finding comfort zones. They don’t need that.”

The alternative ceremonies at Harvard had printed programs, and incorporated the pageantry, ritual and solemnity of traditional commencements, though without the diplomas, which were reserved for the official university commencement.

A few hours after the new “Harvard University Black Commencement” for the graduate schools, including the prestigious law, divinity, business, government and medical schools, about 120 students attended the third annual “Latinx” commencement. In the cavernous basement of a science building, where an animal skeleton dangled overhead and Latin music played, students received stoles with the words “Clase Del 2017” woven into them, while siblings devoured chocolate cupcakes.

Black undergraduates held a separate event that night amid the polished pews and Greek columns of Memorial Church, Harvard’s spiritual center and the backdrop for Mr. Zuckerberg’s address.

While Mr. Zuckerberg’s speech was broadcast live and received thousands of complimentary comments on Facebook, the black ceremony was relatively small and more intimate, and seemed invisible to scores of classmates noshing on sliders and beer at a white tent nearby, part of the broader commencement week revelry.

The ceremony was open to all students, though virtually everyone who attended was black, and not all black students attended.

About 80 black graduates formed a procession to organ music, received kente-cloth stoles, listened to a classmate play Bach on cello and sang “Lift Every Voice and Sing.”

“For me, the black community is a home away from home,” Olivia Castor, a student speaker from Spring Valley, N.Y., who earned a bachelor’s degree in social studies and African-American studies, said exuberantly.

“It’s where I spent most of my time, where I found my closest friends and, more importantly, where I’ve learned the most important lessons during my time here,” she went on. “So thank you, thank you for being beautiful, brilliant and blackety-black-black.”

Brandon M. Terry, the faculty speaker, joked that Harvard College’s black graduation had become more mainstream since he graduated in 2005.

“This setup already has us beat,” he said. “We were in one of the old Harvard buildings across campus. We had no air-conditioning, and some folding chairs on the stage.”

Professor Terry suggested that the mood was different as well.

“You began college just weeks after George Zimmerman was acquitted in the callous killing of Trayvon Martin,” Professor Terry, an assistant professor of African and African-American studies and social studies, said in his address.

“You were teenagers, like Michael Brown when he was subjected to the Sophoclean indignity of being shot dead and left in the blazing sun. Your world was shaped in indelible ways by these deaths and others like them, and many of you courageously took to join one of the largest protest movements in decades to try to wrest some semblance of justice from these tragedies.”

But like all the speakers, he spoke reverently of Harvard as an institution, saying: “The dramatic privileges that you have and will continue to benefit from in virtue of your association with this university are only worth the social cost if they are to benefit people worse off than you.”

Bhekinkosi Sibanda, a first-generation Harvard student from Zimbabwe, said he had been ambivalent at first about participating in the black graduation.

“In an attempt at inclusivity, we don’t want to end up introducing exclusivity,” he said. “You don’t want to end up where this black commencement overshadows the entire commencement of the school. You don’t want to blow away the glory.”

Then Mr. Sibanda remembered how a professor had asked if he wanted to drop a class, when all he wanted was help. “It’s good to be able to take this time for solidarity and identity,” he said, “to celebrate what we’ve achieved.”