Bren Bataclan watched from behind a tree as a young couple approached the fountain in Dupont Circle and studied a small square object leaning against the base of the monument. From his hiding spot, he could see the woman reach down with empty hands, then stand back up clasping a canvas. The duo held a brief conference, their mouths moving but their words too faint for Bataclan to hear. Finally, they reached an agreement that pleased Bataclan: The woman walked off with the artwork, grinning broadly.

The painting was Bataclan’s eighth giveaway of the day and the 114th since he set out this summer on a cross-country expedition supporting his SmileyB project. More important, with this canvas, he released two more smiles into the world.

“I like to help others, and in my own small way, I’m doing that,” said the 44-year-old Boston-based artist. “When I’m leaving paintings around, for 90 percent of the people, it’s an enhancement to their day. For the other 10 percent, it’s an intense, more direct easing of pain.”

Bataclan arrived in Washington July 20, stop No. 39 on his 50-state (plus a District) tour that will mark the 10-year anniversary of his creative endeavor. His mission: Deposit art around the country with the return promise that the recipient will crack a smile more often. In the off-chance that the image of a whimsical worm or a cuddlesome panda doesn’t turn that frown upside down, he attaches a note to each 8-by-10-inch canvas that reads, “This painting is yours if you agree to smile at random people more often.”

“I asked her, ‘Will you legitimately smile more often at people,’ ” David Fiedler, the Dupont fountain finder, said he asked his companion, Alyssa Kahn. “And she said, ‘yes.’”

This weekend, after a marathon drive along a route that is coincidentally shaped like a crooked smile (trace West Virginia, Kentucky, Kansas, Nebraska, Colorado and Wyoming), Bataclan checked off his 48th state (Iowa). After a short respite in California, he will cross off the last square on the map, Oklahoma.

SmileyB originated in a city that often knits its brows and grimaces. Bataclan, who was born in the sunny Philippines and grew up in neighborly San Francisco, attended graduate school in Ohio, where he sampled the Midwest’s special blend of conviviality and chumminess. When he moved to Boston, he noticed a chill in the air that was unrelated to the winter temperature. In 2003, unemployed and antsy, he started depositing his anime-inflected artwork around the city — on park benches, outside banks, inside post offices and at the airport. He hoped his works would thaw the faces of Bostonians.

On a dreary February day in 2004, his art helped a woman in pink sunglasses who, in turn, assisted him in discovering his true calling. The mystery individual was from Greece and had just completed her first chemotherapy treatment in Boston when she stumbled upon his artwork. She later contacted him (he puts his Web site on each note), thanking him for the jolt of hope on an otherwise bleak occasion. (Bataclan has received numerous e-mails from people sharing their tragic situations and explaining how his artwork has changed their attitude toward life.)

“This is my ministry,” said Bataclan, who supports himself as a professional artist and funded his tour through Kickstarter. “Even without money, I will give away one or five paintings a month. She started me doing this indefinitely.”

Bataclan’s strategy is to drop and run. No waiting around, watching and wondering whether the art will find a caring custodian or will end up wet, cold and alone. He scouts for areas with heavy foot traffic and benches — all the better to exhibit the art. If he can’t locate an elevated platform, he will rest the piece on a step or the ground. He prefers dark or neutral backgrounds that will defer to the gumdrop colors of his paintings. Rain, wind, darkness and disaffection are his nemeses.

“After 10 years, I’m happy just leaving it,” he said. “I’m at peace knowing they will find a home.”

At the Mall

In Washington, Bataclan started at the Mall, which is rife with benches and dense with feet. From his tote bag, he pulled out a canvas, a sheet of white paper with the “instructions” and a roll of tape. He set up his bait: a cherry-red worm with yellow antennae and a beatific smile that could melt a butterfly’s heart.

A pedestrian in a black shirt and backpack eyeballed the painting, then looked back over his shoulder to make sure that, yes, a worm was beaming at him.

“Adults are more tied into product placement and think nothing is free.” said Bataclan, who has observed several distinct sociological behaviors over the years.

Another man, this one dressed in orange plaid shorts, stopped and snapped a picture of the canvas. “If my son were here,” said Jalla Haddad of Oregon, “I would be asking him, ‘Where do you want to put it?’ ” However, his son was back home, and Haddad was traveling by motorcycle and camping out for five weeks. There was no room on his bike for a happy bug.

After a few more minutes, a trio of coed-types appeared. Nicole Reed broke from her pack of friends to snag the artwork.

“I was intrigued because of the bright colors, and then I read the note,” said Reed, who had driven up from Gainesville, Fla., that morning. “He’s coming to Gator Nation.”

Bataclan next set up two paintings on a bench near the National Museum of Natural History. The pair received a few sniffs but no takers. Moving closer to the crowds, he placed a canvas among the flowing sea of legs on the museum’s staircase. A member of a large group wearing matching reunion T-shirts knocked the canvas with her foot. It nearly toppled over.

“They’re on steps, not a bench,” he said. “That’s the risk I’ve taken.”

Bataclan switched to the right side of the stairs, away from Team Reunion. Within seconds, Trey Wilhoite of Tysons Corner grabbed the piece. When asked about his intentions for the art, he said that he and his three friends were going to transport the painting to another location. They were considering the steps of the Capitol or the National Air and Space Museum.

“You have to keep spreading the message to random people,” he said.

Maryland and Virginia

After leaving behind six paintings at the Mall, Bataclan slated the remaining nine for Dupont Circle. Pedestrians picked up the paintings as quickly as squirrels popping bird seed. Among the recipients: a birthday girl turning 24, a family visiting from Pittsburgh (one for the 7-year-old daughter, one for the “I want what she has” 3-year-old son) and a student with the Fund for American Studies.

“I definitely can keep this promise,” said Gaby Broque, the student. “I already smile a lot.”

With the D.C. portion now complete, Bataclan set his compass for Bethesda. He sprinkled the pieces around downtown, leaving a few by the Metro station, another in front of a Chipotle, many on benches outside the shops and restaurants. Minutes after depositing the last canvas in Maryland, he caught sight of 9-year-old Patrick O’Donnell running in circles as he hoisted the painting and shouted, “It’s mine, it’s mine.” His mother, Kristin, gently reminded her youngest son that he had to smile at “random people and not your mother.”

The clock was inching toward dinnertime, and Bataclan still had to tackle Virginia before moving on to West Virginia the next day. On his way to the car, he revisited the drop spots in Bethesda, checking on the status of the art. All but one of the benches was empty.

“So there is only one unloved one,” he said, looking over at the painting languishing by the Dunkin’ Donuts.

Later that evening, in a hotel room in Herndon, Bataclan received an e-mail that opened with, “We were wandering around downtown Bethesda and sat down on the bench in front of Dunkin Donuts,” and ended with, “The painting has found a new home.”

The couple included a photo of themselves. They were holding up a painting of a yellow worm, and were smiling from ear to ear.