When Sidwell Friends School asked President Barack Obama if he would like to speak at his elder daughter's graduation this spring, he declined.

"I'm going to be wearing dark glasses," he told a group of lunch companions during a visit to Detroit earlier this year, "I'm going to cry."

Obama was true to his word Friday. He did not speak at Malia Obama's commencement ceremony, which he and the first lady attended along with family and friends of other graduates of the elite private school in Northwest Washington.

"He was just a total dad," the mother of a graduating senior said of the president. "No fanfare. You didn't know they were there."

If the president did cry during the outdoor ceremony, his tears were hidden behind his sunglasses.

Inside the gates of the school's campus, nestled in the woodsy fringe of Tenleytown, Malia was just one of 127 graduates. Like the other young women, she wore a white dress - the young men were in suits - and walked down the stairs of the Zartman House administrative building to take her seat on the lawn beneath vines of wisteria.

Over recent months Barack and Michelle Obama have expressed sadness and pride as their daughter has grown up. But primarily, they have been protective as Malia transitions to adulthood and out of their cocoon. She will turn 18 next month and has been accepted to Harvard. Her parents have said she will take a gap year, allowing her to enroll after her father's term ends.

Sidwell did its best to close the ceremony to the press. The Obamas, who also celebrated the 15th birthday of younger daughter Sasha on Friday with a post-ceremony luncheon at Georgetown's Cafe Milano, wanted to treat the event as a family affair - and the school and others in attendance tried to respect that desire.

Obama drew no attention to himself, and there was no special attention paid to the first family during the ceremony. Sidwell, which also educated the children of Bill Clinton, Richard Nixon, Herbert Hoover and Teddy Roosevelt, emphasizes equality among its Quaker traditions: Awards are not handed out at graduation, and VIPs get no special recognition. (Though after the ceremony, the president and Malia posed for a couple photos with well-wishers that quickly ended up on social media.)

"You have important people, dignitaries. But they are treated like everyone else," said Giulia Adelfio, a 1979 graduate who attended school's graduation ceremony last year.

"They try to make it as seamless as possible for everyone. There's no hoopla around the first family here," said Phronie Jackson, whose son graduated in Malia's class Friday.

The president, meanwhile, has spent less time on campus than his wife, perhaps seeking not to disturb the community. Visits by the first lady and her entourage to the school have caused relatively little fuss, said Robin Gaillard, whose daughter graduated from Sidwell two years ago. "However, when President Obama came on campus, things tightened considerably."

Special security measures were taken so that the Obamas could attend graduation, but other parents said the presence of Secret Service had not been overwhelming - until Friday morning, when police lined Wisconsin Avenue around the school and guests had to pass through metal detectors.

The ceremony, usually open to the public, required tickets this year. And one attendee noted that the traditional class pranks played on administrators seemed to have fallen by the wayside this year.

Like her classmates, Malia Obama walked across the stage to receive her diploma from Mamadou Gueye, the principal of Sidwell's upper school. She also heard a commencement address from the poet Elizabeth Alexander, a 1980 Sidwell graduate and who was launched to national prominence when she read an original work at Obama's 2009 inauguration.

It was the closest the low-key Sidwell ceremony came to presidential pomp. When Chelsea Clinton graduated from Sidwell in 1997, her father spoke. Joe Biden, who has had three grandchildren attend the school, gave a commencement speech in 2012.

But on this day, Barack Obama, who built his political career through soaring oratory, was quiet.