Mary Lou Mace says she called Disney officials, but they wouldn't give her any information about where Chris was staying because of security concerns. The passports also are used to open your hotel room, she says.
Aaron, 17, was concerned that Chris would get his wallet back.
"I knew he probably needed his money to do things with," Aaron says.
The next day the Maces went to the front desk of their hotel, the Port Orleans, and explained the situation to the lobby receptionist.
The receptionist located Chris Drennon, who was staying with his family at the Board Walk hotel several miles away.
Mary Lou Mace went back to the room, and a telephone operator connected her with Chris Drennon's mother.
The two talked about 20 minutes. Mary Lou Mace found out that Chris was 15 and had two brothers, and that the $20 was all he had.
If the passport hadn't been returned, the family would have had to buy another one, because lost passes aren't reissued.
"She had told her son he could forget about finding it, because there were about 80,000 people there, and the park was full," Mary Lou Mace says. "He was really tickled."
They left the wallet with the receptionist, and the Drennons came to pick it up.
The Maces, of Smithsburg, aren't sure where the Drennons live. Mary Lou Mace thinks the Drennons might live in New Jersey, while Aaron believes it could be Ohio.
Aaron and Chris never met, but Chris sent a thank-you note to Aaron's hotel, along with a big box of SweeTarts.
Aaron doesn't think returning the wallet was a big deal.
"Any one of my friends would have done this," he says.
He and some friends recently had a discussion about it, and they came to the same conclusion.
"It's the way we've all been raised," he says.
Aaron, who plays football and lacrosse and runs indoor track, was a lifeguard last summer.
He says he often misplaces things.
"I lose money all the time," he says. "I leave things everywhere. My friends' houses are laced with things that belong to me."
On the same trip to Disney World, he lost $13 on the bus when it fell out of his pocket.