ST. PAUL — Maybe “little” isn’t such an apt description anymore of those book houses people put up in their yards.

Five years after Todd Bol put up the first Little Free Library in front of his house in Hudson, Wisconsin, the grassroots book lending program has popped up everywhere from Iceland to Tasmania. There are about 25,000 Little Free Libraries around the globe today and it’s growing faster than ever.

“We’re going to pass McDonald’s by Thanksgiving,” Bol told Minnesota Public Radio News. “There’s going to be more Little Free Libraries than McDonald’s, which is great.”

The founders will celebrate their success on Sunday with a party at the Minneapolis Central Library. Not bad for a phenomenon that started out with unemployment and the remnants of a discarded garage door.

In 2009, Bol lost his job with a nursing scholarship company and took a soul-searching cross country road trip in his minivan. Returning home, he decided to get a fresh start. So he turned his garage into a home office.

“I had this beautiful garage door and I didn’t want to throw it away in the garbage, and I stared at it for about two months,” he recalled. “I decided to turn it into a one-room schoolhouse that honored my mom,” a former school teacher who died in 2001.

Bol put his doll-house sized tribute to her in his front yard in Hudson and filled it with books she’d left behind. “It was just one, and I never intended to have more,” he said. “It was just to honor her.”

It sat that way until May 2010. “One day, we had a fateful garage sale,” Bol said. “People came up to the Little Free Library, and they acted like they’d just discovered a new little puppy or a kitten.”

Bol thought he might have a hit on his hands. He salvaged some wood from a barn and started building the miniature libraries to meet the demand.

He sold only one initially and gave away about 30 of them in the first year. But the seed was planted.

Part folk art revival, part sharing economy and part book club, the idea took off. Bol started a nonprofit in 2012, funded by sale of the libraries and accessories. About 14 people work there now.

The libraries cost about $300 for a basic model — deluxe versions sell for $1,000 or more — but most people build their own.

Official registration in the Little Free Library directory costs about $40.

“They’re building community. They’re putting books just on our everyday path as we’re walking down the sidewalk. And they’re really letting people be more creative,” said Margret Aldrich, author of a new book on the Little Free Library phenomenon from Coffee House Press.

“The personality that people put into their libraries is amazing,” said Aldrich, who maintains a little library on her lawn. “I’ve seen Little Free Libraries that look like owls, that look like robots, that look like Victorian mansions. The diversity is just amazing.”

And the hosts, called stewards, say they get back more than they give.

Marilyn Meyer put up one in her front yard in Rochester, Minnesota, about four years ago. She’s lost track of how many books she’s put out.

She gets surplus books from the library. She says kids park their bikes on the sidewalk to stop and read them in the summer.

“One summer I had a mom and her little toddler, and they would sit out underneath the tree and read a book every night,” Meyer said. “It was pretty cool.”

Bol said he hopes to spread that further as the idea evolves. He’s seen versions crop up as neighborhood tool and seed exchanges.

He just sent 25 libraries to the Los Angeles Police Department, part of an initiative to put the exchanges in front of police stations and establish a new link between neighborhoods and the cops who patrol them.

The free library group partners now with the Library of Congress and its Center for the Book unit, which promotes book reading and literacy.

“The gentleman that’s in charge of the Center for the Book said that Little Free Library is the hottest literacy movement in the world,” Bol said. “I thought, ‘OK, I’ll take that.’”