The United States is full of fine people who have devoted their lives to our schools. Few, however, have had the chance to do that with as much depth and breadth as Larry Cuban, professor emeritus of education at Stanford University.

Cuban is 87. He has written 22 books. He was a high school history teacher in low-income schools and then superintendent of the diverse Arlington, Va., school district before diving into research and writing. He focuses not on theory but on what’s happening in classrooms. That leads to juicy topics, such as why computers haven’t improved teaching and why U.S. history classes split between praising the country and studying documents.

In his new book, “Confessions of a School Reformer,” Cuban sums up what he has learned. There are surprises: The pandemic has revealed resilience in public support for schools. Also, long-term positive changes have been overlooked in our squabbles.

Cuban is decidedly not a soldier in the army of experts demanding major reforms now. He said that when he was young, he thought smart teachers could band together and triumphantly overturn racism, tight district control and schools organized by the age of their students.

“I confess that I have tempered the unvarnished optimism I had initially about the power of schools to mold individuals and societal institutions,” he said. “I have come to understand the political and organizational forces at work inside and outside schools whenever reformers see their rhetoric of change morph into a mud-filled slog.”

In the book, he gives the pandemic credit for teaching important lessons. Our struggle with the coronavirus revealed an “increased appreciation among single mothers, families with two working parents, and extended families for the custodial function of schools,” he wrote. “All American children ages five to sixteen have to go to school (ages vary by state). Compulsory enrollment legally requires schools to take care of students. Minors in the eyes of the law, children have to learn content and skills, interact with peers and adults, and receive community services, including meals, while within brick-and-mortar buildings.”

Seeing what happened during the pandemic, we might want to engrave those words on school walls instead of fanciful slogans such as “A Building with Four Walls and Tomorrow Inside.”

Cuban’s long career extinguished his youthful hopes about making big social changes. He was convinced early by the many reports, particularly sociologist James Coleman’s analysis in 1966 showing that racial segregation hurts children. “As a teacher, district office administrator, and later superintendent, however, I could do little to put any of the report’s conclusions into practice. Not for a lack of will or knowledge but simply because I worked within school systems for reform, which meant, at best, incremental changes in school structures and the daily business of teaching and learning.”

“I came to realize that a district system was itself nested within larger socioeconomic, political, and caste-like structures (e.g., market-driven society focused on individual action, economic inequalities, racist structures), all of which hemmed in what superintendents, principals, teachers and students could do in making classroom, school and district changes.”

Americans’ abiding faith in our schools overlooks the fact, Cuban said, that “events occurring outside schools shape children and youth as much if not more than the fifteen thousand hours they spend in classrooms and schools during their careers in age-graded schools. What appears like a lot of time is only 20 percent of the total time children and youth spend outside of school.”

He acknowledged that it took him many years to recognize that off-school events, “from hurricanes to pandemics to being wealthy or unemployed and homeless ... weigh more heavily in shaping lives.”

So what are we going to do to make schools better? Cuban’s long life and love of history led him to accept reality but also the possibility of some changes under what social scientists label “dynamic conservatism.”

If we consider what has happened over the long haul, he said, we can see improvements obscured by our bickering over the latest hot reform. “Where once there were bolted-down desks, now movable furniture dominates classrooms. Where once large group instruction occurred in elementary school classrooms, now the prevailing pattern is a mix of small group, partner activities, individual work, and whole group instruction. Where there were once fifty-plus students in many classrooms, there are now twenty-five-plus. Where once high school schedules contained daily forty-minute periods, many schools now have blocks of time when teachers meet with students for sixty to ninety minutes a few days a week.”

I am not quite as old as Cuban, but I know high school instruction is deeper now for many students than when I was a teenager, with more opportunities for acceleration. We have more examples than ever of impoverished children being given the challenging lessons they deserve.

As our living standards have improved, so have our schools. If we continue to do what we can to help our fellow Americans, education will get better. But, as Cuban said, it is often going to be a mud-filled slog.