Crack erupted across America’s marginalized urban neighborhoods in the 1980s like a biblical plague torn from the pages of Revelation. The drug offered an inexpensive, nirvana-like high, leaving users clamoring for ever larger doses in a hopeless yet insatiable quest to sustain the same levels of bliss. It was the perfect “superdrug,” and Black communities, redlined in concrete city blocks, were neglected as their wealthier white neighbors escaped crack’s worst embrace. Those left behind absorbed the brunt of an apocalyptic epidemic that redrew a generation with ruthless precision across racial and economic fault lines.

Donovan X. Ramsey came of age in a crack-era neighborhood in Columbus, Ohio, where it was better not to ask questions. “It was like growing up in a steel town where nobody talked about steel,” he writes in “When Crack Was King,” his panoramic social history of the rise and fall of the epidemic. His book offers a needed corrective to the period’s biased media coverage and tropes — “crackhead,” “crack baby,” “superpredator” — the impetus behind some of the country’s most draconian drug legislation.

Ramsey, a freelance journalist, draws the epidemic’s contours, tracing its roots to the hard-fought advances of the civil rights era and the rise of a nascent Black middle class in the 1960s and early ’70s, developments that triggered a backlash in the form of President Richard Nixon’s ill-fated war on drugs. In a diary entry from 1969, Nixon’s chief of staff H.R. Haldeman wrote that Nixon “emphasized that you have to face the fact that the whole problem is really the Blacks. The key is to devise a system that recognizes this while not appearing to.”

Nixon achieved this goal, Ramsey argues, by switching from a focus on organized crime and wholesale importers of narcotics to one on the users themselves, criminalizing already marginalized Black and brown communities. As president, Ronald Reagan amplified the strategy. Spurred by the moral panic surrounding the 1986 death from cocaine of the basketball star Len Bias, Reagan signed into law the Anti-Drug Abuse Act, passed the same year.

Notoriously, the act mandated a five-year minimum prison sentence for the possession of five grams of crack, while the equivalent sentence for possessing powder cocaine required 500 grams, thus enshrining into federal law the disparity between “Negro Cocaine Fiends” (the title of a 1902 article in the weekly Medical News), and Hollywood hipsters caught taking a “bump” at parties. The legislation swelled America’s prisons with its poorest citizens.

Years later, Lennie was combing the carpet looking for tiny fragments of crack to smoke when her 2-year-old son, a pacifier in his mouth, dropped to his hands and knees to aid her efforts, plucking up lint and offering it to her hopefully. She realized she had to stop and entered rehab, only to relapse.

From the outset, cocaine democratized the drug game. It broke the Italian mafia’s monopoly on street narcotics, principally heroin, as Colombian cartels flooded major American cities with cocaine for as little as a tenth the cost per gram. For underprivileged Black and Latino youths, becoming a crack dealer was an opportunity to escape the generational cycle of poverty. The drug, Ramsey writes, promised to be “their Gold Rush, their Homestead Act, their Prohibition.” One of his subjects, Elgin Swift, dealt crack on the side in Yonkers to make money for bus fare, food and other essentials in a neighborhood where everyone, including Elgin’s father, seemed to be either using crack or selling it.

Shawn McCray, a basketball prodigy from the Hayes Homes in Newark, was caught with crack and narrowly escaped prison when a judge showed him mercy. He went on to graduate from Caldwell College with a degree in sociology. He vowed to go straight and took on a 9-to-5 job, only to succumb to the gravitational tug of the streets to hustle with the Zoo Crew, one of Newark’s biggest drug-trafficking rings in the early 1990s. (McCray eventually gave up dealing and went on to coach boys’ basketball at his former high school.)

Ramsey aims to give the story of the crack epidemic a human face while telling it from start to finish, a herculean task. By and large he succeeds. With a focus on deliverance for his characters as they get sober or stop dealing drugs, he leaves less explored the homicide epidemic that crack ignited — the violence that was an inevitable part of business for operations like the Zoo Crew. Still, he includes an account of Kurt Schmoke, once a zealous Baltimore prosecutor who sought the death penalty for a crack dealer guilty of gunning down a Black detective. Schmoke went on to become Baltimore’s mayor, and, in an impressive volte-face, resolved to try to halt the suffering brought on by crack by decriminalizing users. His biggest successes came in 1994, when he inaugurated a needle-exchange program and a drug-treatment court intended to help addicts avoid jail.

Yet it was not politicians but, rather, people in crack-riddled communities who finally brought an end to the epidemic. By the mid-1990s a new generation had come of age, determined to reject the drug’s grip on minority neighborhoods. Marijuana, accompanied by the bass lines of Dr. Dre’s triple-platinum 1992 album “The Chronic,” supplanted crack. This younger generation heeded the cautionary tale of the 1991 movie “New Jack City” and the street justice meted out to its murderous protagonist, the Harlem crack kingpin Nino Brown. The movie’s antidrug message was in stark contrast to the glamorization of the heroin-trafficking mafia dons in “The Godfather” — yet more evidence of the disparity with which America defines its anti-establishment idols.

Jonathan Green is the author, most recently, of “Sex Money Murder: A Story of Crack, Blood, and Betrayal.” He is working on a book about a group of politically radicalized Christians who formed a deadly armed militia.