When Craig Steven Wilder first began digging around in university archives in 2002 for material linking universities to slavery, he recalled recently, he was “a little bashful” about what he was looking for.

“I would say, ‘I’m interested in 18th-century education,’ or something general like that,” Mr. Wilder said.

But as he told the archivists more, they would bring out ledgers, letters and other documents.

“They’d push them across the table and say, ‘You might want to take a peek at this,’ ” he said. “It was often really great material that was cataloged in ways that was hard to find.”

Now, more than a decade later, Mr. Wilder, a history professor at the Massachusetts Institute of Technology, has a new book, “Ebony and Ivy: Race, Slavery, and the Troubled History of America’s Universities,” which argues provocatively that the nation’s early colleges, alongside church and state, were “the third pillar of a civilization based on bondage.”