Two men, John Hay and John Nicolay, can claim much of the credit for the popular image of Abraham Lincoln as the noble leader and shrewd political operator that's embraced by most Americans today.

In the years after Lincoln's assassination, American perception of the Civil War was viewed through an increasingly popular frame of sectional reunion. Journals fed the narrative that the bloody war was an ugly brothers' spat and papered over the role slavery played in the conflict.

Early biographers, informed by Lincoln's former Springfield law partner William Herndon, wrote first takes of the president that would be unrecognizable to the heroic image that Americans know today from books like Doris Kearns Goodwin's Team of Rivals and Daniel Day-Lewis' Oscar-winning performance.

And the public made Josiah Holland's Life of Lincoln, which erroneously portrayed the president who was gunned down on Good Friday as "an eminently Christian president," an instant best seller. Other early depictions portray Lincoln as bumbling and deeply flawed.

With his new dual biography, Lincoln's Boys: John Hay, John Nicolay, and the War for Lincoln's Image, Joshua Zeitz explains how the two men who served as Lincoln's secretaries shaped the perception Americans have of the 16th president.

Hay and Nicolay, as Zeitz writes, were alarmed by the revisionist Southern apologia that had taken hold and it motivated them to write — after fits and starts in their efforts — the 10-volume biography that would help enshrine Lincoln as the Great Emancipator, unrivaled orator and brilliant political tactician.

As the president's personal secretaries, a job in those days that was a hybrid of chief of staff and valet, Hay and Nicolay — whom Lincoln called "the boys" — had plenty of material.

They were in the room when Lincoln signed the Emancipation Proclamation, and traveled with the president to Gettysburg for the seminal address. Hay and Nicolay — who shared a bedroom in the White House — would stay up late into the night with Lincoln when he could not sleep.

Their behemoth effort, as Zeitz notes, had plenty of critics for its sometimes self-involved tone, incredible length and unabashed bias for the man Hay and Nicolay affectionately referred to as the "Tycoon."

But Hay's and Nicolay's work, as flawed as it may have been, would be the base on which countless Lincoln scholars would build their work.

The Zeitz book comes after last year's publication of the well-received All the Great Prizes by John Taliaferro, a biography of Hay, who after working as Lincoln's secretary became a newspaper editor, poet and secretary of State for William McKinley and Theodore Roosevelt. Hay also married the daughter of a Cleveland industrialist and would become extraordinarily wealthy.

Zeitz doesn't offer any pretenses of his work being a comprehensive account of the life and times of Hay and Nicolay, but it nevertheless neatly fills a hole in the crowded study of Lincoln.

The work can be seen as two conjoined books. The first tells the story of two young men spending four grueling years in the White House by Lincoln's side. The second half details their effort and difficulties in writing the coda to Lincoln's life.

In the most vivid moments, Zeitz offers a window into the psyche of two young ambitious men in the White House who struggled to contend with internal politics (they were often on the wrong side of Mary Todd Lincoln) and who were plagued with uncertainty.

As extraordinary as was the moment that they lived, Hay and Nicolay acknowledged they often missed the significance of events and moments in real time. The two notably spent much of Lincoln's 24-hour trip to Gettsyburg drinking with reporters covering the trip.

They were actors in "stirring times," Nicolay wrote to the woman he would later marry. "I hardly realize that they are so even as I write them."

Lincoln's Boys

By Joshua Zeitz

Viking, 400 pp.

*** out of four