This might seem an odd moment for a study of the books presidents have written. In contrast to former president Barack Obama, a voracious reader and accomplished writer whose books earned the praise of critics and rang up impressive sales, our current president boasts that he has not read a book in his adult life, notably including the books he supposedly wrote.

In “Author in Chief,” Craig Fehrman invites readers to consider, in the words of his subtitle, “the untold story” of our presidents’ books. That claim at first strains credulity. The writings of John Adams, Thomas Jefferson, James Madison, John Quincy Adams, Abraham Lincoln, Theodore Roosevelt, Woodrow Wilson, Franklin D. Roosevelt and Obama, far from being overlooked or ignored, have been exhaustively studied by generations of scholars.

But Fehrman’s book has a different objective. He tells little-known stories about how presidents, or their ghostwriters, produced, published and sold their books. He delves into how many books were printed, bought and read, and how much presidents earned.

Fehrman offers a breezy, anecdote-rich account of the memoirs and autobiographies that have helped candidates running for office. He makes no attempt at comprehensiveness, and the reasoning behind his selections is elusive — and quirky. Readers learn about familiar and unfamiliar books: those written by presidents and their ghostwriters, but also others that veer away from the output of presidents, such as the Bible, almanacs, “Jaws” and “The Da Vinci Code.”

Fehrman begins with our early presidents. He gives us a detailed account of Washington’s “complex partnership” with Alexander Hamilton and tells readers who wrote what in the first president’s Farewell Address, but he says nothing about the ideas in it.

Jefferson was a great reader but not a voluminous book writer. “I cannot live without books,” Jefferson wrote, and a granddaughter recalled that books “were at all times his chosen companions.” His only book, “Notes on the State of Virginia,” went through 19 editions and sold at least 20,000 copies, which, by Fehrman’s estimation, is the equivalent of more than a half a million books adjusted for today’s population.

John Adams’s “Autobiography,” Fehrman writes, “blinks and breathes and quivers with life,” as his political writings do not, making him, at least in the author’s opinion, “the most entertaining writer among the founders.”

In the 19th century, politicians increasingly turned out memoirs as campaign books. The writing shifted from ideas and policies to character and personality. The writings of Andrew Jackson, a colorful veteran of wars and duels, exemplified this change. Jackson’s nemesis, the erudite and prolific John Quincy Adams, Fehrman writes, produced a 51-volume diary that stands as “a great work of literature in his or any other American age.”

Lincoln worked hard to get his debates with Stephen Douglas into print, making it a “new kind of campaign book” offering the candidate’s own words rather than words about him. It sold an “astonishing” 50,000 copies, Fehrman reports, which would be equivalent to more than half a million copies today. Fehrman contends that the book, which the Boston Courier described as “a marshaling of sentences unsurpassed in the most brilliant speeches of American orators,” made Lincoln president. Readers interested in what Lincoln said about liberty, equality and democracy, however, will not find it in “Author in Chief” — they have to read the debates themselves.

Ulysses S. Grant’s “Personal Memoirs” is a “classic,” Fehrman writes, because of the “immediacy” and “directness” of his prose and the intensity of his “feelings,” qualities Fehrman attributes to Grant’s having read a lot of fiction. The two-volume set was a smash, selling 325,000 copies. Theodore Roosevelt wrote 37 books and Wilson 12, “depending on how you count,” Fehrman offers in calculating the output of each man. Yet except for Roosevelt’s “The Naval War of 1812” and Wilson’s “Congressional Government,” Fehrman provides little about their writings, noting only that Roosevelt appealed to readers’ senses and Wilson to their minds.

Instead Fehrman devotes a chapter to “Silent Cal” Coolidge. “Have Faith in Massachusetts” is, in Fehrman’s view, “a really good book,” and it did as much to make Coolidge president as Lincoln’s speeches did for him. Coolidge’s later “Autobiography,” offering his folksy wisdom, earned him half a million dollars (about $10 million today), making him the first former president to become “fabulously rich” from a memoir.

Since the 1880s, presidential writing has aimed to portray what Grover Cleveland called “a snappy life.” With the dawn of the 1920s, as movies and magazines created a cult of celebrity, the public began to crave “dishy details,” Fehrman observes. The poster boy remains John F. Kennedy, who left the dishing on his life to other writers and concentrated on producing works of history, with considerable ghostwriting assistance.

Fehrman presents Ronald Reagan as a man keen on reading — Coolidge’s “Autobiography” was a favorite — and skilled at writing. Reagan’s son Michael remembered that his father “was always at the desk, writing. Not almost always. Always.” Reagan wrote his own speeches, Fehrman assures us, and penned some for Goldwater in 1964. His early autobiography, “Where’s the Rest of Me?,” which Fehrman calls “a remarkably rich campaign book,” not only sold more than 200,000 copies but also propelled Reagan to the California governorship and the presidency.

The final chapters of “Author in Chief” offer breathless accounts of the money that publishing conglomerates have shelled out for blockbusters written by former presidents and their aides: $2.5 million to Richard Nixon; $7 million to Reagan; $15 million to Bill Clinton; more than $60 million for the memoirs of Michelle Obama and Barack Obama; and millions for the books said to be written by Tip O’Neill, Ted Kennedy, Colin Powell and Sarah Palin. The content of these books is irrelevant, Fehrman writes, because they emerged in an era when mega-publishers’ bet that the hype surrounding books matters more than their quality.

Fehrman treats Barack Obama’s books with less cynicism. While “Dreams From My Father” isn’t technically a campaign book, “The Audacity of Hope” fits that mold. It manifests Obama’s careful thinking about American history and politics as well as his considerable skill as a writer.

Most presidents’ books have aimed to entertain, and that might also be said of “Author in Chief.” But Fehrman has done his homework. His bibliographical essays are impressively thorough, particularly on works on the study of writing, publishing and reading. His readers will learn a lot about how our presidents’ books have been written, published and sold. To learn what is in them, however, they will have to follow the guidance Fehrman offers and read the books themselves.

Author
in Chief

The Untold Story of Our Presidents and the Books They Wrote

By Craig Fehrman

Avid Reader/Simon & Schuster.
434 pp. $30