Lincoln’s Boys: John Hay, John Nicolay, and the War for Lincoln’s Image. By Joshua Zeitz. Viking; 390 pages; $29.95. Buy from Amazon.com, Amazon.co.uk

AMERICANS crave books about Abraham Lincoln. But finding fresh material on their 16th president is tough. So some writers are turning to his acolytes—the cabinet, the generals, the son.

A new account, by Joshua Zeitz, focuses on Lincoln’s two secretaries, who had an insider’s view of a momentous presidency. John George Nicolay and John Hay shared a bedroom at the White House and served as Lincoln’s gatekeepers and letter-writers. The president called them “The Boys”. They called him, privately and devotedly, “The Tycoon” and “The Ancient”.

The secretaries accompanied Lincoln from Illinois to Washington in 1861. Nicolay, born in Germany but mostly raised in America, was a former newspaperman who had once walked 35 miles to get a job. Hay was a Brown University graduate and would-be poet, aimless until he began working for Lincoln after the 1860 presidential campaign.

Hay and Nicolay were very different. One reporter described Nicolay, the senior of the secretaries, as a “grim Cerberus of Teutonic descent”. He fiercely guarded Lincoln from the crush of favour-seekers. Hay was more relaxed and jovial, with “both eyes keeping a steady lookout for the interests of ‘number one’”, as another reporter put it. The youthful secretaries, both born in the 1830s, drank and partied during an 1863 visit to Gettysburg with Lincoln. Only later did they appreciate the import of what they had witnessed.

History owes much to John Hay’s literary flair. Once, Hay wrote, Lincoln arrived to share a midnight laugh with his “short shirt hanging about his long legs and setting out behind like the tail feathers of an enormous ostrich”. Hay and Nicolay tried to avoid riling the president’s wife, Mary Todd, whom they referred to as “The Hellcat”, or even “the enemy” or “Her Satanic Majesty”. “The Hellcat is getting more Hellcattical, day by day,” Hay wrote to Nicolay in 1862.

Exhausted by four intense years in the White House, Hay and Nicolay were already planning to take posts in Europe even before Lincoln was assassinated. Mr Zeitz follows them through these early post-war sojourns, though they are not especially interesting. Hay, who wonderfully described Napoleon III as moving “with a queer, sidelong gate, like a gouty crab”, would ultimately become an important figure in his own right, a grand old man of the Republican Party. He capped off his career with seven years as secretary of state under Presidents William McKinley and Theodore Roosevelt, a story ably told in “All the Great Prizes”, a biography by John Taliaferro that was published last year.

“Lincoln’s Boys” is reinvigorated when Mr Zeitz returns to his core subject: the work Hay and Nicolay did with Lincoln’s legacy. Even while the civil war raged, they formed a plan to write their boss’s biography. After the assassination Lincoln’s eldest son, Robert, took control of thousands of administration papers. He gave the secretaries first crack (the papers would not be open to the public until 1947) and they promised Robert he could delete what he wished. Around 1874 Hay and Nicolay started their work. By 1890 they had produced a ten-volume biography.

“Abraham Lincoln” had mixed reviews and did not sell well. Americans found it too long, though they eagerly raced through the shorter, serialised magazine version. Another common complaint held that it was more about the era than the president. “It is a great pity that it should be marred by those personal details of an obscure Illinois lawyer which we notice have crept into the story from time to time,” one reader grumbled sarcastically.

But the book proved fundamental to the shaping of Lincoln’s story. It came out at a time, Mr Zeitz writes, when Americans were conveniently forgetting that slavery had driven the Union apart. As for Lincoln himself, the public had been feeding eagerly on tabloidy reports of a past (and by this point long-deceased) love and a rocky marriage. Hay and Nicolay hammered hard on slavery, skimped on painful personal details and built a case for the wise and compassionate leader that Americans revere to this day.

“I believe he will fill a bigger place in history than he even dreams of himself,” Hay wrote to a friend in 1863. Thanks partly to his and Nicolay’s endeavours, he was to be proved right.