BIDDEFORD — Click. One photo was taken. The three Small brothers stood next to the school bus that brought the Biddeford High football team to Waterhouse Field for its annual game with rival Thornton Academy. They wanted a second photo, this time with their father.

Minutes before Friday’s kickoff there was still time for a keepsake moment. Pending one final vote of the Maine Principals’ Association next month which may or may not be a formality, one of the fiercest high school football rivalries in Maine ended when time ran out on the scoreboard.

Thornton Academy 41, Biddeford 20. Late in the fourth quarter, Thornton Academy students sounded the familiar chant: It’s all over. It’s all over.”

As quickly as the words were shouted, they were silenced. Maybe the students understood the poignancy. These two teams may meet again. But the Battle for the Bridge, named for the crossing over the Saco River that separates Biddeford and Saco, will be played for pride only. Citing declining enrollment, Biddeford has asked to moved to Class B. Thornton Academy, a perennial contender, will remain in Class A.

Graham, Steve and Casey Small smiled for the photos. Sad smiles. Starting with Graham in 1980 and Casey in 1991, the brothers have five Biddeford state championship jackets between them. Casey can still wear his. His brothers outgrew their jackets.

They were boys when they played for Coach Mike Landry, who demanded success. Their father grew up across from Waterhouse Field on West Street. A nearby side street is named for their grandfather, Wendell.

The history of Biddeford football and its rivalry with Thornton Academy is broad, but the Small family lived the best chunk of it.

“I would have thought there would be more people here,” said Casey. “Oh well. I guess we’ll find good seats.”

Nostalgia and pining for a time gone by doesn’t win football games. Thornton Academy led at halftime, 14-7. Biddeford played well and with emotion to keep the score close.

In the second half, Thornton Academy’s edge in talent, size and depth became more apparent.

The Small brothers remembered when the bleachers on either side of the field and behind one end zone were full of cheering, yelling fans. They remember games at Thornton Academy when fans stood five deep, ringing the field. They remember hearing later that the 50-50 payout to a lucky fan would be $6,000 and more.

“As a kid, playing in front of 10,000, you knew it was a big game,” said Steve Small. “When you pulled up in the bus people seemed to be everywhere.”

In 1991, Biddeford met Thornton Academy in the playoffs. The winner went to the state championship game. Thornton Academy had Art Leveris at running back. He would win the Fitzpatrick Trophy as the state’s best high school player. Casey made more than a few tackles on defense that day. Biddeford won 29-28, then beat Gardiner for the Class A title, the fifth and last for the Small family.

“People still say that game with Thornton Academy was the best high school football game they ever saw,” said Casey Small.

John Webb grew up in Sanford and played football for Sanford High in the late 1970s when its rivalry with Biddeford was second best. He went to TA-Biddeford games when he could. “There would be people there for as far as the eye can see. C’mon, it’s Thornton Academy and Biddeford. As far as I was concerned, it was the only rivalry.”

Webb’s son, Jack, is a freshman lineman for Thornton Academy. “If Jack wasn’t on the face of the earth I would be here tonight. Are you kidding me?”

Michael Roberge graduated from Thornton Academy in 1964. His younger brother, Don, graduated in 1970 and was a star player. “The games were thrilling and they were friendly. Sure, they could be intense. But afterward we went to these big dances, Biddeford kids on one side, Saco kids on the other. We’d walk around. We’d mingle on the dance floor.”

Friday night, Thornton Academy fans cheered lustily for the big plays on offense and defense and the touchdowns that came more frequently in the second half. Biddeford fans shouted their encouragement for the smaller victories.

Jimmy Smith, a former Biddeford player, was with his young son, Dominic. “Why am I here? It’s Biddeford football.”

Everything has changed, he was saying. But not the team, the rivalry or the ideal.