But most people probably don’t realize the tradition started with a plucky group of history buffs in 1987.

At the time, the newly formed Apex Historical Society was looking for a way to spread the word about its existence and to promote the downtown.

So the tree-lighting ceremony was born.

The group is no longer in charge of the holiday event; these days, the Historical Society has set its sights on another endeavor: reflecting on its own 25-year history.

Past group leaders, including founding president Jan Brooks, will be honored during a special ceremony Sunday. The event is free and open to the public.

In 1987, Apex was a tiny town of about 3,000 residents, but Brooks sensed growth was on the horizon. She wanted to preserve the town’s history.

“There were so many natural resources that could have been lost,” Brooks said. “We realized we really needed to bring in the citizenry, to bring to their attention what was in Apex – so the future could see what we see.”

Brooks said preserving history is contagious.

“You instill this pride of place. People love to feel that your roots are important,” she said. “I’m proud of the fact (the society) has been sustainable. I’m proud of what it’s done to downtown Apex.”

At the reception Sunday at the Halle Cultural Arts Center, the group will show a 30-minute film that highlights its history.

The group’s accomplishments are plenty: It acquired a 55,000-pound train caboose for demonstrations, helped kickstart the effort to get local landmarks on the National Register of Historic Places and launched the popular annual downtown home tours.

The group also bought and restored the Maynard Pearson House, an 1870 home whose former owners were related to Samuel Pearson, who started Yates Mill, now the only remaining grist mill in Wake County.

In honor of its 25th anniversary, the Historical Society is hosting an open house of the Maynard Pearson House every third Saturday of each month from 2 p.m. to 4p.m..

Eventually, the group hopes to open the house as a museum.

“It’s a milestone,” said Claire Rousseau, a founding member, about the 25th anniversary. “It’s an achievement that a small group of people were all able to come together, not necessarily all born in Apex, who could make a lasting impression in Apex.”