There are certain motifs in Jonathan Kozol’s half-century of writing about America’s failure to adequately educate poor Black and Hispanic children, which began with “Death at an Early Age,” a blistering account of his year teaching in the Boston Public Schools.

Decrepit school buildings with rancid bathrooms and leaking ceilings. Students stultified by scripted curriculums and endless test prep. Bleak urban neighborhoods with neglected parks, crumbling apartments and harried, underpaid teachers. The despair is punctuated by bright and vivacious children, who bluntly note the obvious unfairness that adults have trained themselves to overlook.

“Death at an Early Age,” published in 1967, turned him into the sort of widely read public intellectual hardly present anymore.

Now, at 87, he has published “An End to Inequality,” his 15th book — and his last, he says. It is an unapologetic cri de coeur about the shortcomings of the schools that serve poor Black and Hispanic children, and thus, the moral failure of the nation to end the inequality he has documented for decades.

Critics have long said that Mr. Kozol has focused too much on all that is wrong in American public schooling, and not enough on models for success. They point to the charter schools, charismatic principals and early-reading programs driving change, even in some deeply segregated neighborhoods.

But Mr. Kozol characterizes those as marginal reforms meant to plug into a system that is unequal by design. And in his long career, he has seen decades of national reform efforts — “A Nation at Risk,” No Child Left Behind, Race to the Top, Every Student Succeeds — come and go, while some problems remain much the same.