Morrie Turner, at work in his studio, was the first African American to have a cartoon strip syndicated in mainstream newspapers that featured an integrated cast of characters. (Courtesy of Creators)

In the 1950s and early ’60s, Morrie Turner was a police department clerk in Oakland, Calif., and he moonlighted drawing cartoons for magazines such as Black World and Ebony.

“I couldn’t participate in the civil rights marches in the South, and I felt I should,” he later told the San Francisco Chronicle. “I was working and had a wife and kid. So I decided I would have my say with my pen.”

One of his favorite panels from that era featured a black woman trying to identify a suspect in a police lineup; she sees three white men with obvious physical distinctions. “I don’t know!” she announces. “They all look alike to me!”

For Mr. Turner, who died Jan. 25 at 90, the transformative moment of his career was a meeting with “Peanuts” creator Charles M. Schulz at a cartoonists’ convention in the early 1960s.

As Schulz used children to address mature matters of faith, friendship and wonder, Mr. Turner used children to address the crescendoing civil rights movement. He said he hoped to do with a comic strip what the activist and comedian Dick Gregory did with a stage.

A "Wee Pals" comic by Morrie Turner, where the character Mikki uses books to help reach her goal, a jar of cookies. (Courtesy of Creators)

In 1965, Mr. Turner launched the strip “Wee Pals,” which featured a multi-ethnic crew of moppets and made Mr. Turner one of the first mainstream black cartoonists. Ebony called it “the first truly integrated strip.”

The playmates included an African American named Nipper (an homage to comedian Nipsey Russell), who wears a Confederate Army cap and has a canine named General Lee; the chubby white intellectual Oliver; a bullying white boy named Ralph; a Latino named Pablo; an Asian American named George; a spirited feminist named Connie; the Jewish Jerry; the deaf and mute Sally; and the bespectacled Charlotte, who is in a wheelchair.

Mr. Turner said the intent of the strip was to promote tolerance and understanding, dubbed “rainbow power.” He once wrote that of wanting “to portray a world without prejudice, a world in which people’s differences — race, religion, gender and physical and mental ability — are cherished, not scorned.”

The Sunday strip featured a panel called “Soul Corner,” which showcased high-achieving black men and women.

The tone of the strip is resolutely positive. When Nipper proved a flop at baseball and said that he would never be another Hank Aaron, he dusted himself off and decided to follow the path of black intellectuals such as Frederick Douglass and George Washington Carver.

“Wee Pals” took a few years to catch on. It seemed to reach its syndication peak — running in about 100 newspapers — months after the 1968 assassination of the Rev. Martin Luther King Jr. “People realized how white everything was,” Mr. Turner told the Los Angeles Times. “They finally realized what Dr. King was talking about.”

Since 1990, “Wee Pals” has been distributed by the Hermosa Beach, Calif.-based Creators syndicate and is seen in about 40 newspapers and a dozen Web sites, said Creators founder Rick Newcombe. It reaches about 2 million readers, he said.

“Wee Pals,” which ran for a time in The Washington Post, also inspired an animated TV show called “Kid Power,” broadcast on ABC in the early 1970s.

Mr. Turner wrote books featuring the “Wee Pals” cast in addition to inspirational volumes about black history such as “Super Sistahs.” He often lectured to schoolchildren about his “rainbow power” message and received humanitarian awards from the Anti-Defamation League and B’nai Brith, the Jewish service organization.

In 1970, he served as vice chairman of the White House Conference on Children. Mr. Turner said at the time, “I thought that just by exposing readers to the sight of Negroes and whites playing together in harmony, rather than pointing up aggravations, a useful, if subliminal, purpose would be served, and ultimately would have as great effect for good as all the freedom marchers in Mississippi.”

Within a few years after the launch of “Wee Pals,” Schulz added to “Peanuts” a black character named Franklin, and cartoonist Mort Walker of “Beetle Bailey” introduced the Afro-sporting Lt. Flap. Mr. Turner was credited with helping break ground for black cartoonists such as Brumsic Brandon Jr. (“Luther”), Ray Billingsley (“Curtis”), Darrin Bell (“Candorville”) and Aaron McGruder (“The Boondocks”).

Mell Lazarus, the novelist and cartoonist who started the “Momma” and “Miss Peach” comic strips, called Mr. Turner’s work charming, accessible and imbued sensitively with a message about racial equality. “It was a wonderful way to do it,” said Lazarus, a former president of the National Cartoonists Society.

Mr. Turner was a 2003 recipient of the society’s lifetime achievement award.

Morris Nolten Turner was born Dec. 11, 1923, in Oakland, and was the youngest of four children of a Pullman porter and a homemaker. In interviews, he said that his ethnically diverse neighborhood inspired his cartoon characters.

“White, Filipino, Japanese, Chinese, black — it was a rainbow,” he told the San Francisco Chronicle. “I didn’t know that wasn’t the way it was other places. Oakland was that way before the war. We were all equal. Nobody had any money.”

Aside from a correspondence course in drawing, Mr. Turner received no formal training as an artist. He drew comic strips for military newspapers while serving in the Army Air Forces during World War II.

After his discharge, he married, had a son and took a clerical job with the Oakland Police Department. He became a full-time cartoonist in 1964 with “Dinky Fellas,” which featured a group of black children and was modeled on the timeless gentle humor and irreverence of “Peanuts.” “Dinky Fellas” appeared in two black newspapers, the Berkeley (Calif.) Post and the Chicago Defender.

The comics impresario Lew Little began syndicating the strip, which grew in its cast of characters and was soon rechristened “Wee Pals.”

The National Cartoonists Society announced Mr. Turner’s death, at a hospital in Sacramento, and said that the cause was complications from dialysis treatment.

Mr. Turner’s wife, Letha Harvey, whom he married in 1946, died in 1994. Survivors include his companion, Karol Trachtenburg of Sacramento; a son from his marriage, Morris A. “Morrie” Turner of Hercules, Calif.; four grandchildren; and nine great-grandchildren.

Mr. Turner, who lived in Sacramento, continued to write “Wee Pals” in recent months and saw his work as an ongoing struggle against intolerance.

“That’s what I’m supposed to do,” he told the San Jose Mercury News. “I think, what am I supposed to be doing that I’m not doing? My mother used to say, ‘Cast your bread upon the water.’ By saying that to me, it meant that I should give a little.”