For a moment, Ernie Rehr, walking through the basement of his alma mater, had a flashback. It was a vision of his old history teacher, Mr. Houston, voice booming, chasing him back to class, Rehr said Saturday at an open house celebrating Frankford High School's 100th anniversary.

"It was just an awesome high school experience," said Rehr, Class of '76. "Every teacher and coach looked out for the well-being of the students here. And the athletics, the best in the city."

Rehr was one of about 500 alumni crowding the halls of the castlelike school to see old friends, rehash tales, thank memorable teachers, and celebrate a century's worth of pride.

Since Frankford opened in 1910 as an annex to Central High, more than 56,000 students have graduated. Most came from working-class families, and they went on to become doctors, lawyers, engineers, teachers, professional athletes, and just ordinary good citizens.

Throughout the school were many points of pride: the hallway of murals, the stained-glass windows, and the auditorium's old pipe organ, the only fully functioning pipe organ in a city public school, many alumni testified.

Frankford High is also the "Home of Champions," as proclaimed on a big red, blue, and gold banner out front, and as noted in display cases for the wrestling, field hockey, football, and other teams.

At the open house, the school's fight song brought a few tears. And alumna after alumnus talked about the school spirit.

"Even though some of us came from different neighborhoods," said Rehr, who grew up in Somerdale and played baseball for his school, "when we came to Frankford High School, we were all one spirit."

"Frankford is a school of tradition," said a teary-eyed Tony Visco, Class of '56, in a navy suit and tie in the school colors. "Your heart is here."

In the library, on round tables, displays honored each decade.

On the 1910 table sat a black-and-white reunion photo of the "optimist club," a half-dozen white boys in suits and ties, holding a big gold trophy. Other early pictures, of the French Club, a literary club, showed girls in sweaters and skirts, never pants.

Over the years, the school's demographics diversified and its dress code loosened.

The 2000 photos show an array of students, white, black, and Latino, laughing, dancing, achieving.

Nearby, Dawn Hodson-Ritzler, Class of '77, wearing her original Pioneer Marching Unit pin, flipped through her yearbook to show her young daughter who her mother once was.

"You look like me, Mommy," her 9-year-old cheered.

Next to Hodson-Ritzler, her father, his hair thin and silver, looked through the Class of '54. He showed his granddaughter his photo, above the name Harry Albert Hodson. Hodson flipped some more and smiled at a picture of his younger self in a black choir robe, his brown hair slicked.

Hodson-Ritzler, who drove to the open house from her home in Pitman, recalled with a laugh how on her first day at Frankford, her history teacher had asked if her father had sung in the school choir. He had. Her aunt also went to Frankford High, as did Hodson-Ritzler's brother and sister.

"It was a family thing," she said, smiling. "They went to Frankford, I was going to Frankford."

On the third floor, culinary-arts student Rolande Augustin, Class of 2010, donned a chef's jacket as she chatted with alumni.

"This year has been so exciting," she said. Celebrity chef Rachael Ray recently surprised Augustin and her classmates with an extreme kitchen makeover and college scholarships.

Augustin plans to major in culinary arts, work in France, and return to Philadelphia to open a French restaurant.

And she helped prepare some of the food for the open house. "I love this class," Augustin said. "It was like working in a real restaurant, where people scream, and if you mess up, you get fired."

Heading to the cafeteria, three old girlfriends, Bernice '62, Donna '60, and Carole '60, in chic, pixie haircuts, teased and laughed, like old times.

The friends still keep in touch through Facebook and meet every couple of months for facials, massages, and dancing or dinner, but being back at Frankford High conjured dusty memories.

Back then, Donna and Carole (her name tag missing an e), already friends, took Bernice, in another clique, under their wing.

"And we taught her how to shave her legs," said Donna Sutton-Connolly.

The conversation turned to the school's strict dress code, and how girls had to wear stockings.

"You couldn't even wear culottes," shouted Bernice Stein-O'Neill.

The firm rules; the football games, where throngs of students followed the team, cheering, as it walked to the stadium; the lifelong friends.

"It was the best school," Carole Nussbaumer-Graham said with a smile.