Mr. Powell appears in the film “American Anarchist,” released in 2017. (Courtesy of Patna Pictures LLC/Gravitas Ventures)

“I don’t like to think that I contributed to people being killed,” William Powell once said, wrestling with what he had wrought as a disaffected 19-year-old when he hunkered down with military manuals and revolutionary writings and compiled “The Anarchist Cookbook.”

His volume — a guide to drugs, booby traps, sabotage, hand-to-hand combat and explosives — entered circulation in 1971 and reportedly sold more than 2 million copies. Still in print, and accessible online in PDF form, the book has been linked in recent years to the perpetrators of crimes including the 1995 Oklahoma City bombing, the 1999 massacre at Columbine High School in Littleton, Colo., and the 2011 Tucson shooting that wounded then-U.S. Rep. Gabrielle Giffords (D-Ariz.).

Mr. Powell, who has died at 66, ultimately renounced his book, which he described as a “misguided product of my adolescent anger at the prospect of being drafted and sent to Vietnam to fight in a war that I did not believe in.” He became an educator, working in schools around the world.

“The central idea to the book was that violence is an acceptable means to bring about political change,” Mr. Powell wrote in an author’s note that since 2000 has accompanied the book’s listing on “I no longer agree with this.”

Mr. Powell died July 11 of a heart attack while traveling with his family near Halifax, Nova Scotia. A son, Sean Powell, announced the death shortly afterward on Facebook. The news did not receive wide notice until the release on March 24 of a documentary film about Mr. Powell, “American Anarchist,” by director Charlie Siskel.

Efforts to reach Mr. Powell’s family were not immediately ­successful.

Siskel, who said the family had notified him of Mr. Powell’s death, said in an interview that he saw “The Anarchist Cookbook” as an example, however extreme, of something “quite universal”: “a youthful indiscretion or mistake that can haunt someone during their early years or even longer.”

Mr. Powell was born in December 1949 on Long Island. His father’s work as a U.N. spokesman took the family to England, where Mr. Powell said teachers caned him “fairly regularly.” When he returned to the United States, he was teased for his British accent. In an unpublished memoir, Mr. Powell wrote that he was molested, Siskel said.

Mr. Powell was managing a New York City bookstore when he received his draft card and, in 1968, set about putting together the manifesto that became “The Anarchist Cookbook.”

“This is not the age of slender men in black capes lurking in alleyways with round bombs, just as it is not the age of political discussions in a Munich beer hall,” he wrote, calling upon the “real people of America” to resist fascists, capitalists and communists. “This is a truly unique age, where the individual has become the supreme agent of anarchist theory.”

“The revolution in this country has already started,” he continued. “It is a battle between the poor blacks and the rich employers. It is a battle between the artists and the censors. It is a battle between the Black Panthers and the police. It is a battle between the welfare mother and the bureaucracy of the city, and surprisingly enough it encompasses the yearly battle between the taxpayer and the Internal Revenue Service.”

He warned that the book’s do-it-yourself subject matter was illegal and not to be used by “children or morons.” In about 160 pages, he provided instructions, complete with illustrations, on projects such as converting a shotgun into a grenade launcher, making tear gas and TNT and destroying bridges.

First printed by the maverick publisher Lyle Stuart and later distributed by other houses, the book attracted the scrutiny of the FBI. As recently as 2015, U.S. Sen. Dianne Feinstein (D-Calif.) argued that its contents should be removed from the Internet.

Mr. Powell noted that the book had not been difficult to research. He had simply gone to the library and gathered information readily available elsewhere.

Three years after the book’s publication, he received a bachelor’s degree in English literature from Windham College in Putney, Vt. He left the United States in 1979, the same year he received a master’s degree, also in English, from Manhattanville College in Purchase, N.Y., according to an online biography.

His name forever tied to the revolutionary guide, Mr. Powell at times struggled to find work. He eventually listed the publication on his résumé, Newsweek reported in a 2011 profile, having concluded that it was better to acknowledge his past than let potential employers happen upon it.

His teaching career took him to the Middle East, Africa and Asia. With his wife, Ochan Kusuma-Powell, he wrote the book “Becoming an Emotionally Intelligent Teacher” and co-founded Next Frontier: Inclusion, a nonprofit serving children with developmental and learning disabilities. He described the effort as a form of atonement.

“The Cookbook has been found in the possession of alienated and disturbed young people who have launched attacks against classmates and teachers,” he wrote in a 2013 renunciation of the book published in the London Guardian. “I suspect that the perpetrators of these attacks did not feel much of a sense of belonging, and the Cookbook may have added to their sense of isolation.”

He said that although the reason for his anger — “unnecessary government-sanctioned violence” — continued, he could no longer endorse a militant response. He requested that the book be removed from print but said he lacked the authority to pull it from shelves because the copyright was held by the publisher.

A complete list of survivors was not immediately available.

“To paraphrase Aristotle: it is easy to be angry,” Mr. Powell wrote in his Guardian mea culpa. “But to be angry with the right person, at the right time and to the right degree . . . that is the hallmark of a civilized person.”