The Rev. Arnold Townsend was in a long, unshakable funk. His only child, Rachel, had died 10 months earlier, at just 38 years old. They were a team, described by a friend as like “bread and butter,” and he had lost his other half.

He was tying his shoes before heading to a meeting about naming an affordable housing complex in the Western Addition after Rachel, one of the few bright spots in a dark year.

Something compelled him to stop and check his email on his phone. And there it was. A message that would finally pull him out of his grief.

“My name is Natalie Douglas. I’m not sure how best to go about writing this note,” it began.

She was an acclaimed jazz and cabaret singer in New York City who’d learned she was adopted. She had her DNA tested through Ancestry.com, as Townsend had done a few years before.

“We are a match as Parent/Child,” the email continued. “Please get in touch if you feel so inclined. And either way, thanks for the genes!”

Townsend replied the next day. One daughter lost. One daughter found. And two lives that would never again be the same.

Townsend has lived in San Francisco for more than a half century and has long been a pillar of the city’s shrinking African American community. He was member of the Black Student Union at San Francisco State University during the famous student-led strike in the 1960s, and he was jailed three times during the protests.

Now 76, the Fillmore resident is the board president of the African American Art & Culture Complex, the nonprofit formerly run by Mayor London Breed, a longtime friend. He’s also the vice president of the San Francisco NAACP and an associate minister at Church Without Walls, a Baptist congregation. He moves with old-school swagger — often donning a suit, fedora and bow tie, and carrying a wooden walking stick.

Townsend’s daughter, Rachel Brooke Townsend, was raised by her mother in Oakland, but spent a lot of time with her dad in San Francisco. After growing up surrounded by political activism, she became a community organizer.

Together, the two Townsends ran the city’s annual Juneteenth Parade and Festival to commemorate the end of slavery. Rachel, an urban cowgirl who participated in rodeos, rode a horse in the parade when she was a little girl and became a key organizer of the entire event as a teenager.

Her father said they were so tight, they couldn’t stay mad at each other for more than an hour before they’d burst out laughing.

“Rachel and I always rolled together,” Townsend recalled. “All I had to say was ‘Let’s’ and she’d say ‘go.’”

Supervisor Vallie Brown, a longtime friend of Rachel’s, said the father-daughter pair were like “bread and butter.”

“It seemed like such an easy relationship,” Brown said. “You didn’t feel any strain.”

But the jovial relationship ended after Rachel collapsed at home on Dec. 19, 2017. A vein had burst in her neck, brought on by cirrhosis caused from too much drinking, her dad said. She was surrounded by family in her room at Oakland’s Highland Hospital when a doctor said there was no hope and asked who was responsible for making the decision to remove life support.

All eyes turned to Townsend, who reluctantly agreed. Rachel died on Jan. 4, 2018.

“You feel such a defeat,” Townsend said of outliving a child. “A daddy always feels like he should take care of his baby, and though you know it’s illogical, if you’re honest with yourself, you feel like such a failure.

“Or at least I did.”

A few years before, Townsend had been curious about his roots and had his DNA tested through Ancestry.com. He learned he was descended from people in Nigeria, Mali and other West African countries.

“And this is a good one — Scandinavia!” he said with a laugh. “Some English and a teensy bit Asian. I don’t know how that got in there.”

Three thousand miles away, Natalie Douglas also wanted answers about her heritage. She’d been raised by a loving family in Southern California, but only after her parents died in the early 2000s did she learn through a cousin that they’d adopted her as a baby.

“It changed everything, and it changed nothing,” Douglas said. “They raised me, and they loved me.”

She tried various paths to finding her biological parents over the years, but ran into dead ends. Last summer, she learned of a 2-for-1 sale at Ancestry.com and persuaded her husband, Billy Joe Young, to try it with her.

“She loves a sale,” Young, a personal trainer, said with a laugh.

“It was just shocking that I’m completely white,” he said with an even bigger laugh.

Of course, the real shock was that Douglas found her biological father. She sent the man — username ArnoldTownsend44 — an email introducing herself.

Townsend was on his way to an important meeting when he received the note. He would be talking with residents of an affordable housing project about an idea to name their building after Rachel.

The suggestion had come from his friend Gail Gilman, former director of Community Housing Partnership, a nonprofit that was taking over the operation of 1750 McAllister St., a 97-unit property for low-income seniors and people with disabilities. Gilman suggested naming the renovated building the Rachel Townsend Apartments.

“It was fitting,” Gilman said. “She was a fierce advocate for anti-displacement in the Fillmore.”

Townsend was touched by the idea.

But he was downright shocked —and thrilled — to receive Douglas’ out-of-the-blue message. He was 100% sure the results were correct.

In her email, Douglas described being put up for adoption a month after her birth, and the details of her birth date, birthplace and her last name at birth (which her adoptive parents changed) lined up with Townsend’s high school girlfriend. They broke up when he left for college, and he never knew she’d been pregnant.

“So much to tell you, and I have been crying,” Townsend wrote to his daughter. “You’ll understand better when we talk.”

Townsend and Douglas haven’t stopped talking. They text each other constantly, often late at night when he can’t sleep and she’s getting home from performing.

She flew out to San Francisco soon after they connected on email, attending the Dec. 19, 2018, dedication of the Rachel Townsend Apartments and singing at Townsend’s church on Christmas. She chose “O Holy Night,” his favorite holiday song.

She performed at Feinstein’s at the Nikko in September, and Breed and former Mayor Willie Brown were in the packed audience. Douglas’ husband said Townsend was weeping throughout the entire show.

Douglas and Townsend shared their story with me shortly after the concerts. They gazed at each other with affection, teased each other and chattered so much, nobody else in the room could get a word in edgewise.

“You get a kid late in life, I would have been happy with anyone. But this!” Townsend said, beaming at his daughter. “I could have done worse.”

“Me too,” Douglas told him.

“I could have done much worse,” he said.

He’s planning to visit her in New York soon, and she’s heading back west for a concert in March.

Townsend said finding his new daughter can never make up for the devastating loss of his other one. But she’s certainly made his life a whole lot better and restored his faith in God.

“He always has one more move in your direction, in your benefit,” Townsend said. “If I wasn’t a believer before, I sure am now.”

San Francisco Chronicle columnist Heather Knight appears Sundays and Tuesdays. Email: hknight@sfchronicle.com Twitter: @hknightsf Instagram: @heatherknightsf