A 1952 yearbook from Armstrong High School, which was one of five schools open to black students until a 1954 Supreme Court decision. (Astrid Riecken/For The Washington Post)

Almost 65 years since graduating from Armstrong Technical High School in the District, Thelma Cummings and Clayton Roberts greeted each other Sunday with a warm hug as a ballroom in Prince George’s County began to fill up around them.

“Hey, a classmate!” Cummings, 82, exclaimed. “We went all the way through school together, since kindergarten.”

“All the way,” Roberts responded, “together!”

Around them, as soft jazz played in the background, fellow Armstrong alumni — some with canes and walkers, a few in wheelchairs — greeted each other with “You came!” and “You’re looking good!”

The almost 300 alumni and guests gathered at La Fontaine Bleue in Lanham to celebrate their alma mater, one of five D.C. high schools open to black students before the U.S. Supreme Court declared segregation to be unconstitutional in 1954.

They have been holding the annual reunion and dinner dance every spring since at least the 1950s and probably for decades longer, organizers said.

But Armstrong’s loyal alumni are feeling their age, and their numbers are dwindling quickly. With the defunct school’s last class having graduated in 1958, the youngest members are now reaching their late 70s. The oldest recently turned 100.

After some longtime leaders suffered recent health setbacks, alumni association president John Milligan, 89, said it appears “realistic” to believe it might well have been the historic school’s final spring gathering.

“We don’t have any graduates following in our footsteps,” said Milligan, who retired after 32 years at the U.S. Bureau of Engraving and Printing. “It’s just us old folks hanging in there and being true to the school.”

Doris McCannon, 84, said the alumni group now has about 125 members, down from the 900 or so when she joined in the late 1980s.

“We don’t have anyone to replace those of us who are getting older and tireder,” said McCannon, a retired high school social studies teacher.

It’s not the dining and dancing they’ll miss, alumni say, as much as their proud history of using the event to help a younger group of seniors — generations of high school students who have received college scholarships with the money raised through ticket sales and donations.

The group estimates they’ve awarded more than $500,000 in scholarships — usually $10,000 or more annually — to hundreds of recipients from the D.C. region and beyond. That includes $1,000 each to 10 students this year, with an extra $500 for the highest GPA.

“We have a long list of kids who have graduated from colleges all over the country,” Milligan said.

Founded by Congress, Armstrong opened in 1902 and educated generations of black Washingtonians. In addition to the vocational school’s future auto mechanics and seamstresses, the college prep track produced teachers, musicians, doctors and engineers.

The school building was added to the National Register of Historic Places in 1996, in part because it exemplified Booker T. Washington’s national campaign to promote vocational training for African Americans, along with academics. The educator and orator gave the school’s opening address.

Famous alumni include jazz composer and musician Duke Ellington, who reportedly dropped out to pursue his music career; jazz and pop singer Billy Eckstine, football Hall of Famers Len Ford and Willie Wood; internationally acclaimed opera singer Lillian Evanti; Burtell Jefferson, the District’s first black police chief; and D.C. Superior Court Judge John D. Fauntleroy.

After the technical high school closed in 1958, the building at 1st and O streets NW housed a veterans’ education program and eventually an adult education center — all bearing the last name of Samuel Chapman Armstrong, an educator and commander of an African American regiment during the Civil War.

The D.C. State Board of Education shuttered the adult education school along with other aging campuses in 1996 to save money. The building is now home to the Friendship Public Charter School’s Armstrong campus, which has 3-year-olds through fifth graders.

What made Armstrong remarkable, alumni say, were the devoted teachers and the camaraderie — and often rivalry — they shared with D.C.’s other black high schools, particularly Dunbar High School, the college prep school across the street.

“Most people did everything together,” Cummings said. “If you didn’t know somebody, you knew somebody who knew somebody.”

School spirit revolved around the bands and cadet corps. Boys wore slacks and ties. Girls wore skirts and dresses.

McCannon, a 1952 graduate, laughed when asked why she chose the vocational tech school, even though she pursued a college prep track in addition to the cooking and sewing classes that most girls took.

Her strict mother, she said, hadn’t allowed her to socialize with neighborhood boys, “so I chose a high school with lots of boys.”

Almost 70 years later, she and others are still proud of their Armstrong ties. Even so, time is taking a toll. Their monthly alumni meetings have dwindled to nine or so attendees. Every year, the annual dinner dance loses more classmates.

But some are holding out hope.

“The younger ones — I say the ‘younger ones,’ and I’m 82 — want to keep having it,” Cummings said. “I think once you went to Armstrong, it just stayed with you. We’ve lost so many people, but we’re just sort of attached.”