Pulitzer Prize-winning historian David McCullough, who died last week at 89, was the preeminent historian of his generation. McCullough wrote 12 widely read books but wisely avoided a university affiliation, which is one reason his writing was so lively. Although he wrote books on a wide variety of subjects, almost always in the realm of American history, he was and will be forever known for his link to the American presidency.
McCullough's link to the presidency manifested in a number of ways. Most prominent were his two magisterial presidential biographies, of Harry Truman and John Adams, although he also wrote great works on George Washington and Teddy Roosevelt. The two eminently readable and impressively scholarly biographies on Truman and Adams may have defined their subjects more than any presidential biographies have defined any two presidents. Truman was mostly known as a middling president before McCullough's 1992 biography restored his reputation. Adams was the mostly forgotten Founding Father before McCullough's 2001 take, which was later made into an HBO miniseries starring Paul Giamatti.
But McCullough didn't just write about presidents, he was also read by presidents. George H.W. Bush, not a huge reader actually, spoke once about having "no time" to read but making time to read Truman. As he wrote to former New Hampshire Gov. Hugh Gregg, he had "read McCullough's new book on Truman, and read how Harry put it in perspective." Even back in the '70s, before McCullough became the behemoth that he did, Jimmy Carter reported reading McCullough's bestselling history The Path Between the Seas: The Creation of the Panama Canal. Carter wrote in his diary, "It's obvious that we cheated the Panamanians out of their canal. As a matter of fact, no Panamanian ever saw the  treaty at all before it was signed." This perspective may have helped Carter come around to supporting the return of the canal, but it sure did not help Carter politically. Ronald Reagan used his popular opposition to the treaty to bolster his case against Carter in 1980.
In later years, it became de rigueur for presidents to read McCullough's works. George W. Bush read Truman, after which Condoleezza Rice gave him the memoir of Truman Secretary of State Dean Acheson. As James Mann wrote of Bush's reading on the Truman administration, "Both Bush and Rice were convinced that after September 11 it was time to jettison old doctrines, to challenge existing assumptions, and to create new principles for dealing with the world." Bush also took John Adamswith him on vacation in 2001.
Eight years later, Barack Obama put John Adams on his summer vacation reading list, leading John Dickerson to observe: "The McCullough book seems like the kind of thing presidents get with the job." Sen. Mitt Romney (R-UT) did not succeed in his presidential effort, but as a presidential candidate, he did dutifully report that McCullough was one of the authors on his reading list. In addition to writing about presidents and being read by presidents, he also interacted with presidents. McCullough admired Reagan and interviewed him in the Oval Office for PBS's American Experience. He understood an essential truth about Reagan, which was that "all of Reagan's humor was directed at himself. He never made fun of or belittled others. Like [Dwight] Eisenhower, he was a hard guy to dislike." He also shared Reagan's optimism about America and liked Reagan's inaugural address line: "How can we love our country and not love our countrymen?"
He was particularly admired in the George W. Bush administration. Bush gave him the Presidential Medal of Freedom in 2006, calling him "the voice of history." And Dick Cheney included McCullough as one of the authors he met with as vice president.
McCullough deserved all of the attention, of course, but at bottom, he was a researcher and writer of the highest order. One of the last books he wrote, The Pioneers, was about the settlement of Ohio by Americans in the postcolonial era. That book has one of the best acknowledgments I've ever read. In it, McCullough explained how he was first interested in the subject decades ago and then later came to research at the relevant libraries, thanking the historians and archivists who helped him along the way. It was a powerful window into his method and his dedication to writing. It was that dedication that made him the historian of his generation and one who will be long remembered by future generations.