In 2019, the Yale historian David Blight won a Pulitzer prize, for his monumental biography of Frederick Douglass. In 2020, Blight was beginning work on his next book, about the life of the writer and civil rights activist James Weldon Johnson. Then, his college president called.

“Peter Salovey called me up, in the depths of Covid, and said: ‘Would you lead, manage and write the history of Yale and slavery?’”

It was the year of the police murder of George Floyd, and surging protests for racial justice. Other universities – Georgetown, Harvard, Brown, Princeton – were exhuming and examining the role of slavery in their pasts.

“I didn’t want to spend years of my life studying Yale,” Blight says. “I had another book I had started … I gulped. But I didn’t really have a choice. I run the Center for the Study of Slavery, Resistance, and Abolition. So I said: ‘Yes, but I don’t want to write a report, which is what all the other universities are doing, it’s full of statistics, it’s full of policy options and yada yada. Let’s write a real narrative history. Let’s dig into the archives and tell the truth.’

“And [Salovey] loved the idea. And for the next three years, I had a small research team, I had two or three of Yale’s most brilliant librarians, and that’s exactly what we wrote, a narrative history, and not once did Salovey or anybody in his administration try to control it.”

History is a sensitive thing. As Blight and his team set to work, controversy raged over the 1619 Project, Nikole Hannah-Jones’s recasting of American history to begin when the first enslaved Africans set foot in Virginia. Historians debated. Culture warriors went on the offensive.

Harvard was grappling with the issue of reparations. Yale was not entirely sanguine. Blight “did get queries from the general counsel’s office once in a while. ‘Can you tell us what’s coming here,’ that sort of thing. But that’s their job. That’s fine. No one tried to control a single word of what we did.” The result is Yale and Slavery: A History, a necessary, hugely readable work. Most of the compelling, starkly lyrical text is Blight’s. But it was a true collaborative effort.

“I wrote nine chapters,” Blight says. “Hope McGrath wrote the two late 19th-century chapters and a series of interludes, and Mike Morand wrote the 1831 chapter” about a failed effort to establish a Black college in New Haven. “They were both deeply embedded in the Beinecke Library and the sources, and we all edited each other.”

The story begins in 17th-century Connecticut, amid the brutal subjugation of Native tribes by English settlers. Yale was founded in 1701, the start of the century in which the transatlantic slave trade reached its terrible height. Blight’s introduction puts the case succinctly: “A multitude of Yale University’s founders, rectors and early presidents, faculty, donors, and graduates played roles in sustaining slavery, its ideological underpinnings, and its power.” He and his fellow authors take the story to the 20th century.

The paperback is out, an exhibition at the New Haven Museum has closed. But just as Blight says there is work still to do – “there could be a second volume that takes the story of race at Yale through the 20th century and into the 21st … there are going to be plaques, possibly a major memorial, kiosks around the campus” – so he points out that the Yale and Slavery Project really began years before the George Floyd summer.

“Charleston was the turning point,” Blight says, referring to the killing of nine Black people at a church in South Carolina in 2015. “In June, it’ll be a decade since the massacre at Emanuel AME, and that was what prompted Peter Salovey to initiate campus discussion of the Calhoun name, which led to two years of turmoil.”

John C Calhoun was a South Carolina congressman and senator who became secretary of war, secretary of state, a presidential candidate and vice-president to John Quincy Adams and Andrew Jackson. A ferocious champion of slavery, in the 1830s Calhoun pushed the US to the brink of civil war. From 1933, his name adorned a Yale college. In 2017, amid the turmoil Blight cites, the college was renamed for Grace Murray Hopper, the great computer scientist.

Other colleges still bear slave-owners’ names. Other reminders linger. The final chapter of Yale and Slavery, written by Blight, concerns the university civil war memorial. Erected in 1915, it was a monument to “lost cause” revisionism, treating northern and southern soldiers alike, mentioning slavery nowhere. In 2020, as Blight got to work, protesters across the US vandalized or pulled down statues and memorials to the contested past. Authorities removed others. At Yale, the civil war memorial stands unchanged – but with an informational display installed.

“I’m not advocating removal of anything,” Blight says. “If [Yale and Slavery] leads toward more renaming of this or that site, so be it … [but] this war memorial is deeply embedded inside a major building here, and a major thoroughfare through campus. You could blast it out of there, I suppose, but that would be a tragedy. Better to explain, interpret and revise.”

Yale and Slavery does so. Black Americans are profiled, prominent among them William Grimes, author of “the first slave narrative by an American-born Black person”, the son of a revolutionary war veteran who escaped slavery in Savannah, Georgia, then lived a long and picaresque life in New Haven.

Blight’s book also sheds light on links between New Haven (“and all the New England port cities, really”) and the sugar plantations of the British West Indies, a culture apart from the cotton fields of the American south but every bit as brutal. Blight highlights a quote from Benjamin Silliman Sr, a Yale professor who in 1833 obtained a federal commission to study sugar plantations in Louisiana.

To a fellow professor making a research trip, Silliman wrote: “Open your eyes and ears to every fact connected with the actual condition of slavery everywhere – but do not talk about it – hear and see everything but say little.”

Silliman, Blight says, was undoubtedly “a great scientist, often credited with bringing the natural sciences into university curriculums. He was here for 50, 60 years. But when we found that quote, [we thought], ‘Oh my God, that’s the epigraph.’ He’s telling his colleague: ‘Learn everything you can about slavery, but don’t tell anybody.’ And that kind of became the mode of thought, or even a modus operandi, maybe for Yale itself. Study this, but be careful talking about it. A kind of deeply concerted moderation.

“And then we found Silliman had a Black research assistant, Robert Park, for something like 30 years, a guy from right here in New Haven, who may have been born a slave. We never figured that out. But you get a sense of how deeply embedded certain ideas were in this place. And Silliman, he has a statue, right up on Science Hill. And yes, a college named for him too.”

Silliman came from a slaveholding family. He condemned slavery, but as Blight writes, as with many New Englanders, he remained “trapped in a memory he could neither silence nor control”.

Recently, at Yale and elsewhere, student protest has focused on other issues – prominently Israel’s war in Gaza. But slavery and its legacy remain raw and relevant, especially as Donald Trump’s return to power triggers new attacks on progressive campus initiatives, including attempts to reckon with the racism and its place in American history.

Colleges must tread lightly. Yale and Slavery is a major work of history but as Blight notes, it was not sent out for review: “They didn’t want publicity, at first. They wanted to somehow see what the reaction was without it.”

When it comes to slavery’s lingering ghost, publicity can be uncomfortable. A few years ago, when Grace Hopper College was still named for John C Calhoun, a window in its dining hall showed romanticized images of enslaved people at work in southern fields. A Black college worker took a broom handle and smashed the panes. Reporters descended. Controversy flared. The staffer was not prosecuted. The glass was not restored.

• Yale and Slavery is out now