Charles Best was just 23, a new teacher in the Bronx, struggling along with fellow teachers to pay for copy paper and other supplies out of their own pockets, when he got a bright idea.

He’d create a website where teachers could let the public know what their classrooms need. Strangers then could donate to the projects they like best.

“I figured there must be people who’d like to help teachers like us,” Best said in a phone interview.

Thanks to the power of an idea, the kindness of strangers, the Internet and a little help from Oprah Winfrey, his DonorsChoose.org snowballed and grew in 13 years into a nationwide philanthropy.

It has raised $167 million to help 7 million public-school students and pay for more than 240,000 class projects, from microscopes and art supplies to field trips and life-changing equipment for students with disabilities.

Best, 37, will tell his inspiring story at Montana State University in a free public talk on Tuesday, March 5, at 7:30 p.m. in the Strand Union Ballrooms.

Getting started required bribery and subterfuge. Best created a rudimentary website, but to persuade his fellow teachers to try it, he offered them his mother’s pear dessert. Anyone who ate the dessert had to post what he or she most wanted for the classroom on his fledgling website. Eleven teachers did.

Then he persuaded his aunt, a nurse, to fund one project. Anonymously, he put up money for the rest, figuring he was living at home with his parents and could afford it.

The other teachers were thrilled.

“They mistakenly thought the website worked,” Best said. The rumor spread through the Bronx and the website started getting hundreds of projects posted.

Best then got volunteers from his students to send out 2,000 letters seeking donations. The letter campaign raised $30,0000 for schools all over New York City.

In 2003 Oprah caught wind of DonorsChoose.org, interviewed Best on her TV show and “crashed our website,” he recalled. Donations grew to $250,000. By 2007, it was open to all U.S. public schools.

“Dedicated teachers have awesome ideas for helping their students learn,” Best said. “By tapping teachers’ best ideas, we can enable someone with $10 to become a philanthropist.”

His own first project was to bring in a speaker, a man who’d escaped from modern slavery in West Africa, the subject of a New Yorker profile, to talk to his high school history students, who were studying abolitionist Frederick Douglass.

One of his favorite projects came from a teacher in Oakland, Calif., who had a student, Cindy, with cerebral palsy, who couldn’t speak. The teacher got her to try out a voice output device, which let the girl express her ideas aloud and show that her disabilities were more physical than mental. But insurance wouldn’t pay for the device.

So the teacher posted on the DonorsChoose.org website, “Give Cindy a voice,” and raised $10,000.

The average request is $564 and 82 percent of recipients are in high-poverty schools. The nonprofit has the highest four-star rating from the watchdog Charity Navigator.

To ensure integrity, Best said, DonorsChoose.org screens each request. It doesn’t hand out cash, but directly purchases the supplies or services requested.

Teachers then photograph their projects, write thank you notes to the donors, describing what students are learning. Students also write thank-you’s. It’s the same kind of “rich, vivid feedback,” he said, that billionaire philanthropist Bill Gates receives.

In Montana, DonorsChoose.org has so far raised more than $255,000 for 179 teachers and 321 projects, to help nearly 11,000 students with books, technology, classroom supplies, a field trip and other resources.

Best said he hopes not only that his story will inspire MSU students to feel that they can make a difference in the world but also that “any teacher and any citizen can make a difference.”

Gail Schontzler can be reached at gails@dailychronicle.com or 582-2633.

Locations