Shortly after I started working at The New York Times, a friend in medical school called me and suggested I write about the lily-white, heavily monied culture of medical education.

As I delved into reporting, I learned that every stage of medical training requires deep financial reserves. First come the MCAT-prep courses, the application fees, the flights to schools around the country for interviews. Then, once you’re accepted, there are hundreds of dollars to be spent on textbooks and flash-card banks and tutoring, not to mention the tens of thousands of dollars’ worth of tuition. Some students swipe their parents’ credit cards; others grit their teeth and take out loans, or hold back on buying pricey academic resources (study guides, exam fees) while hoping their grades won’t suffer.

The by-product of this expensive, homogenous medical culture is a field of doctors that represent only a small slice of the American population. Less than six percent of American physicians are hispanic. Only five percent are Black.

And that has health consequences. Studies have shown that Black patients have better outcomes when treated by Black doctors. They’re also more likely to consent to important preventive care, like cholesterol tests and diabetes screenings.

The by-product of this expensive, homogenous medical culture is a field of doctors that represent only a small slice of the American population.

So when I set out to write Life on the Line, a book about medical students during the pandemic—following a group who graduated early to work in New York hospitals overwhelmed by the coronavirus—I knew that I wanted to find subjects who didn’t look or think exactly like the stereotypical, old-school American doctor.

And as I started researching, I learned that the roots of today’s whitewashed American medical field go even deeper than I’d thought.

When Medicine Went Mainstream

Nearly 200 years ago, as modern medicine went mainstream, medical schools started popping up all across the U.S. Over in England, the Royal College of Physicians touted a rigorous standard of professionalism and admitted only Oxford and Cambridge graduates. But on the wide-open American frontier, becoming a doctor was far simpler. A group of doctors would approach a college with a proposal, and the college would give them the legitimacy to confer medical degrees. The instructors were unsalaried and got their money from student fees. Exams weren’t rigorous, because students paid their professors only if they passed.

Then, at the turn of the last century, the American Medical Association decided to reform American medical education. The organization thought the field ought to be more rigorous, less freewheeling. So they commissioned a report, written by a young educator named Abraham Flexner, which concluded that many of the country’s medical schools should be shut down. Only the elite should remain.

That meant many of the medical schools that trained nonwhite and non-wealthy students were shuttered. After the Flexner reforms, only two of the seven Black medical colleges were left. A recent study in The Journal of the American Medical Association investigated how many additional Black physicians would have been trained as of 2019 had five of the shuttered Black medical schools been saved. Their estimate: 35,315.

Even at the time, the Flexner reforms were criticized for the way they eliminated medical schools that supplied poor communities with doctors and gave poor people the chance to study medicine.

At the turn of the last century, many of the medical schools that trained nonwhite and non-wealthy students were shuttered.

At one such school in Tennessee, a doctor wrote: “True, our entrance requirements are not the same as those of the University of Pennsylvania … yet we prepare worthy, ambitious men who have striven hard with small opportunities.” He ends with a plea: “Can the wealthy who are in a minority say to the poor majority, you shall not have a doctor?” As rural schools shut down, that’s what the wealthy effectively did.

What does all this mean in the context of the young medical students I followed last year? Students from under-represented backgrounds enter a field whose training programs have been designed toward exclusivity for more than a century. Medical education has long been structured to winnow down trainees and ensure those licensed to practice represent the most educated, the best trained, those with proper pedigree.

That’s made medicine a challenging field to break into for those without access to high-quality early education and financial resources. It means medical students and trainees don’t always get the opportunity to learn from those who are different from them—people whose parents didn’t go to college, those who grew up without health insurance or medical literacy.

The students in my book, though, are re-writing the country’s medical story. They’re fighting to care for underserved communities, and offering medical care that cultivates trust. And they started their careers doing so last year in the midst of a crisis, right when the country needed them most.

Emma Goldberg’s Life on the Line: Young Doctors Come of Age in a Pandemic is out now from Harper