John C. Nicolay, who had known Lincoln in Springfield, Illinois, served as chief White House secretary from 1861 to 1865. Trained as a journalist, Nicolay had hoped to write a campaign biography of Lincoln in 1860, a desire that was thwarted when an obscure young writer named William Dean Howells got the job. Years later, however, Nicolay fulfilled his ambition; with John Hay, he spent the years from 1872 to 1890 writing a monumental ten-volume biography of Lincoln.

In preparation for this task, Nicolay interviewed men who had known Lincoln both during his years in Springfield and later when he became the president of the United States. "When it came time to write their massive biography, however," Burlingame notes, "he and Hay made sparing use of the interviews" because they had become "skeptical about human memory." Nicolay and Hay also feared that Robert Todd Lincoln might censor material that reflected "poorly on Lincoln or his wife."

Briefer and more narrowly focused than the Springfield interviews, the Washington interviews deal with the formation of Lincoln’s cabinet, his relations with Congress, his behavior during the war, his humor, and his grief. In a reminiscence by Robert Todd Lincoln, for example, we learn of Lincoln’s despair at General Lee's escape after the Battle of Gettysburg: "I went into my father’s office ... and found him in [much] distress, his head leaning upon the desk in front of him, and when he raised his head there were evidences of tears upon his face. Upon my asking the cause of his distress he told me that he had just received the information that Gen. Lee had succeeded in escaping across the Potomac river. . ."

To supplement these interviews, Burlingame has included Nicolay’s unpublished essays on Lincoln during the 1860 campaign and on Lincoln’s journey from Springfield to Washington in 1861, essay’s based on firsthand testimony.