For 40 years, The New Yorker has published William Hamilton’s cartoons of women with ski-jump noses and men in Top-Siders accompanied by lines that wittily deconstruct the ethos of America’s upper classes. More than a dozen of them appear in the holiday hot seller “The Complete Book of New Yorker Cartoons,” taking on topics such as trophy wives, real estate, and dinner party bores.

These days, Mr. Hamilton, 65, is tackling riskier humor onstage with a play he calls a direct descendant of the minstrel show.

“White Chocolate,” which has its 100th performance tomorrow night at the off-Broadway Century Theater, is a farce about race and class in the upper echelons of New York society.

The protagonists are a married white couple who wake up black one morning (the roles are played by black actors). Brandon Beale, a Boston Brahmin with a lockjaw drawl, greets the change with a scream and tries to scrub off the color. His wife Deborah Zucker Beale takes the transformation in relative stride – after all, she’s familiar with the minority experience. She’s Jewish.

Their houseguest, Brandon’s sister, thinks she’s arrived at a costume party, so she assembles her own politically incorrect getup – blackface and a maid’s uniform accessorized with a strong cocktail.

The only person who treats the Beales more or less normally is their daughter’s Chinese boyfriend, Winston Lee, whom Mr. Beale insists on calling “Winthrop” and at one point (after a liberal dose of Scotch), “Won Ton.”

Not that the younger generation is immune to stereotyping: When trying to break the ice with Mr. Beale, Winston asks, “Did you play basketball?”

“Putting a Chinese character in turned out to be really smart. It’s not black versus white, Jew versus Protestant. He sort of throws the whole thing,” Mr. Hamilton said.

The show opened in October and has an open-ended run. It reached production with the help of Mr. Hamilton’s friend and Harper’s editor, Lewis Lapham, who put it in the hands of theater producer Allan Buchman (whose credits include Sarah Silverman’s “Jesus is Magic” and Sarah Jones’s “bridge & tunnel”).

“I think these people were heavenly brave to do it,” Mr. Hamilton said, “but it’s just so out of sync with what is politically correct and entertainment correct.”

So far, he is delighted with the audience response.

“What’s interesting is that there’s a black contingent, a Jewish contingent, and a WASP contingent and they laugh at different times,” he said. “And there’s a big black audience which I love.”

Mr. Hamilton has only one bone to pick, and that’s with some of the critics.

“From what I’ve seen there’s a real prejudice against me because I am a cartoonist. It’s real easy to say it’s a bunch of one-liners. I think the one-liners that work in a play wouldn’t work as cartoons. I may be good at cartooning, but it isn’t the same thing at all.”

Mr. Hamilton’s daily life in New York served as inspirations for the play, specifically noting ongoing segregation in New York’s social world.

“I thought prejudice would kind of end by now, and yet I go to dinner parties and there are no black people, and black people go to dinner parties and there are no white people. We’re all bourgeois now, but we still seem far apart in some bizarre way,” he said.

Then there was his experience in Europe befriending an African-American woman. “We had a great time, because we were American. You go back to the U.S. and you feel the race again,” he said.

Though Mr. Hamilton’s oeuvre has primarily focused on blueblood types, many of his cartoons have included black characters “for no reason at all,” he said. “I have tried assiduously to show what I perceive as the American crowd,” he added.

He recently married a Kentucky horse breeder, which has put him in comfortable financial circumstances. He’d like them to buy an apartment in New York, but she’d rather own a private plane. “I’ve had this bifurcated life, between upper and lower,” he said.

Asked if he feels like an outsider, he replied, “I suppose I’m losing it now with a rich wife, but I used to have no money which was always a help.”

A genteel upbringing in a modest town colored Mr. Hamilton’s views of class.

“I spent my first 10 years in a Napa Valley which had not been gentrified. It was a blue-collar world. My father didn’t work.”

The family’s house was called Ethelwild and had been in the family for generations – but not used continuously.

“This house I grew up in was really, really unusual in the sense that no one had lived there since 1905 or something – since modern life had happened. We moved in there and there was no electricity, and everything was there just as it had been. The drawers were all full of buttonhooks and gloves. The caretaker was a lazy old man. So I grew up in this oddball world.”

He became enchanted by cartoons with while digging through piles of European magazines back at Ethelwild.

“Figaro had these wonderful cartoons in them. Cartoonists then were very famous and they became sort of my idols,” he said.

At age 12, he received his first rejection from the Saturday Evening Post, for a cartoon he’d nearly copied, about burglars complaining about the rain as they burgled the house.

Mr. Hamilton’s country-boy perspective changed dramatically when his mother sent him to the New England boarding school that her father had attended.

“So I went to Andover where everybody’s father was the president of the Ford Company or the president of the United States, and I had this huge adjustment.”

It was the first time he’d been on the East Coast.

“I realized very quickly it was a real fix. There were people I’d been to school with who were just as smart as these guys, who were going to wind up clerks and carpenters. I felt guilty for a little while. I felt out of place in both places, which was an ideal experience for going into the arts.”

Although an awkward teenager, Mr. Hamilton found he could use his sense of humor to gain acceptance.

“I was fantastically late maturing. I was chain-smoking Chesterfields to try to get a voice that didn’t sound like a woman. I was this shy kid from California, not an athlete, but I could talk. I was funny.”

He continued to draw cartoons at Andover and at Yale, and sold his first piece to the New Yorker in 1965, when he was in the army, away from combat, in Alaska.

“I thought I had the most the elegant title: Private, First Class.”

He settled into the life an artist, eventually writing plays and novels in addition to drawing.

“You do what you can in the freelance life,” he said.

He considers his various media “separate activities, and a great relief from each other,” he said.

“When you draw cartoons you can listen to the radio. When you write, you can’t. It’s a lot lonelier writing.”

“The thing about the theater that’s better than writing or drawing is that it’s so collaborative. You’re involved with other people. It comes alive.”

The gratification is significant. “As a complete egocentric person, I’ve written novels and I’ve seen people reading them, but I don’t get to see them sit through every word, like I can with a play – and that can be heaven on a good night.”