From the time of Lincoln's nomination for the presidency until his assassination, John G. Nicolay served as the Civil War president's chief personal secretary. Nicolay became an intimate of Lincoln and probably knew him as well as anyone outside his own family. Unlike John Hay, his subordinate, Nicolay kept no diary, but he did write several memoranda recording his chief's conversation that shed direct light on Lincoln. In his many letters to Hay, to his fiancée, Therena Bates, and to others, Nicolay often describes the mood at the White House as well as events there. He also expresses opinions that were almost certainly shaped by the president

For this volume, Michael Burlingame includes all of Nicolay's memoranda of conversations, all of the journal entries describing Lincoln's activities, and excerpts from most of the nearly three hundred letters Nicolay wrote to Therena Bates between 1860 and 1865. He includes letters and portions of letters that describe Lincoln or the mood at the White House or that give Nicolay's personal opinions. He also includes letters written by Nicolay while on troubleshooting missions for the president.

An impoverished youth, Nicolay was an unlikely candidate for the important position he held during the Civil War. It was only over the strong objections of some powerful people that he became Lincoln's private secretary after Lincoln's nomination for the presidency in 1860. Prominent Chicago Republican Herman Kreismann found the appointment of a man so lacking in savoir faire

Lacking charm, Nicolay became known at the White House as the "bulldog in the ante-room" with a disposition "sour and crusty." California journalist Noah Brooks deemed Nicolay a "grim Cerberus of Teutonic descent who guards the last door which opens into the awful presence." Yet in some ways he was perfectly suited for the difficult job. William O. Stoddard, noting that Nicolay was not popular and could "say 'no'about as disagreeably as any man I ever knew," still granted that Nicolay served Lincoln well because he was devoted and incorruptible. Stoddard concluded that Nicolay "deserves the thanks of all who loved Mr. Lincoln."

For his part, Nicolay said he derived his greatest satisfaction "from having enjoyed the privilege and honor of being Mr. Lincoln's intimate and official private secretary, and of earning his cordial friendship and perfect trust."