New York, Standing before his living-room mirror one morning in August 2001, Vishavjit Singh put his fumbling fingers to the task of wrapping on his turban for the first time in a decade. It slumped to one side. Then the creases were not crisp enough. Finally, he got it right, and headed to his job as a software engineer in suburban New York. Mr. Singh had stopped wearing the turban, an emblem of his Sikh religion, in part because he had not been especially observant while growing up. More deeply, he knew firsthand how that visible symbol marked Sikhs as targets of bigotry, sometimes by Hindu foes in India, sometimes by Americans who assumed anyone in a turban to be Muslim. By this time, though, Mr. Singh had studied and embraced his religion, and spent 18 months letting his hair and beard grow in accordance with Sikh precepts. With several hundred thousand Sikhs living in the United States, a country founded on religious tolerance, why should he keep effacing his identity? Then, about the month later, a brilliant sun rose on the morning of Sept. 11. Strolling outside his White Plains office a half-hour after the planes struck the World Trade Center, Mr. Singh saw drivers giving him the middle finger and heard passers-by calling him “Osama.” Yet none of it, that day or for all the years after, compelled him to give up the turban. So it was that on another crystalline late-summer morning, this one in September 2014, Mr. Singh, 43, stood on a brick plaza of the Alfred University campus in upstate New York, folding and twisting a light-green cloth into a taut band. Holden Whitehead, a linebacker on the college football team, then held one end of the fabric between his teeth, as Mr. Singh circled him clockwise, enfolding the student’s hair in a turban. And, oh, by the way, Mr. Singh was doing this while wearing a Captain America costume, about which more will be said later. Costume or not, Mr. Singh had planted on Mr. Whitehead’s skull not just a form of headwear but an epiphany or two. “I’ve heard of the Sikh religion before, but I didn’t know anything,” said Mr. Whitehead, 20, who was taking a class on diversity and comic art. “Like everyone else, I thought it was Arab.” In this moment of role reversal, it was the white guy from Lock Haven, Pa., who was thrust into the role of being the visible other. “If you’re proud of your religion, just rock it,” Mr. Whitehead said. “But it must be hard to keep your composure, dealing with all the stares.” Stares would qualify as the benign end of the spectrum for many American Sikhs, who follow a monotheistic religion founded in South Asia about 600 years ago. Because they are so often mistaken for fundamentalist or even jihadist Muslims — the turban being associated with the leaders of Al Qaeda, Hezbollah, the Taliban and the Islamic State — American Sikhs have endured a substantial amount of hate crime. While the F.B.I. does not break down separate statistics for attacks against Sikhs specifically, the last 13 years have seen numerous beatings and several killings, most notoriously the fatal shooting of six worshipers at a Sikh temple outside Milwaukee in 2012. Mr. Singh has made it his mission, in deeply felt and highly idiosyncratic ways, to address the ignorance and thus defang the hate. To understand the depth of his conviction, it helps to return to his childhood. Born in Washington, the son of a civil servant in the Indian Embassy, Mr. Singh moved back to Delhi with his family for his schooling. When he was in seventh grade, a wave of anti-Sikh violence engulfed the city — partly provoked by the assassination of Prime Minister Indira Gandhi by two bodyguards who were Sikh, but also abetted by some members of the police and government. As a boy of 13, Mr. Singh peered through the curtained windows of his family’s apartment at a Hindu gang trying to break into the building. Ultimately, a Hindu neighbor hid and sheltered the Singhs for several days until the worst violence abated. By then, several thousand Sikhs had been killed, many burned alive, and tens of thousands had fled their homes. To this day, Sikhs like Mr. Singh refer to the events as a pogrom rather than merely a riot. The memory of human nature at its worst and its best, of marauding mobs and compassionate neighbors, stayed with Mr. Singh even as he returned to the United States for college, then earned a graduate degree and began a career in computer engineering. What did fall away in those years was his boyhood love of cartooning, which seemed like no way to make a living. After the Sept. 11 attacks, though, Mr. Singh found himself compelled to resume drawing, to put his pleas for tolerance in the easily digestible form of comics. Techie that he was, he sketched with his index finger on a laptop’s touch pad and posted the resulting work online. By the end of 2002, he had produced enough cartoons to start a website, sikhtoons.com, which eventually attracted about 1,500 unique visitors a day. Trying to promote his artwork, Mr. Singh attended the New York Comic Con in 2011. For the occasion, he drew up a poster of Captain America, the patriotic character originally created for World War II’s struggle against fascism, but with a Sikh’s turban and beard. A year later, after the mass shootings at the Sikh temple in Wisconsin, Mr. Singh wrote an op-ed column for The Seattle Times, declaring, “It’s time for a new superhero to fight hate crimes.” The blowback online from readers — “dumb column,” “race obsessed left,” “ ‘hate crimes’ is a political invention” — only fortified Mr. Singh’s commitment. He ordered a Captain America outfit and then found a tailor to do alterations for his alter ego, trimming its XL dimensions for his 5-foot-9, 125-pound frame. Sometimes in his casual jeans, sometimes in his neon-bright outfit, always with his turban and beard, Mr. Singh has taken his message about Sikhs and tolerance to audiences from the University of Kansas to the Japanese American National Museum in Los Angeles to the satirical television show “Totally Biased.” At Alfred University, which runs a special program called “Drawn to Diversity,” he found an especially receptive audience for his speech, cartoon presentation and turban-tying workshop. His performance-art stroll through the campus became the occasion for many selfies, fist-bumps and iterations of “Awesome, dude!” “People can think I’m not an American, they can tell me to go home to where I came from,” Mr. Singh told his student listeners at one point. “And I say: ‘O.K., I’ll go home tonight. I live here.’ ”