Allen French was a careful, scholarly writer of history. Several of his historical works on the early American period remain in print today, and more than once he traced undiscovered primary sources which shed new light on the happenings of the American Revolution. Yet, meticulous researcher that he was, history was always more to him than a collection of dry facts. Whether he was writing scholarly works or exciting tales for boys, his endless fascination with the past allowed history to come alive. His wife, Aletta, once wrote that while deeply immersed in what was to be his final major historical work, The First Year of the American Revolution, her husband also wrote a children's book on the Romans in Britain and a novel about the Puritan Migration to America. She says, "His imagination fired his mind to the point where it blazed and he would take to fiction to let off the heat!"
A long-time family friend and an author himself, T. Morris Longstreth, writes of Allen French that "It was hard for him to sit through a meal without our talk driving him to the encyclopedia. Yet there was no pedantry in all this, but rather a sense of adventure, the same romantic sense that led him to write his boys' books. History was for him a living glory."
Perhaps Allen French described his own technique best: "Of the writing of history I have only this to say: that as my fiction was constructed out of imagination guided by common-sense, my history is common-sense illuminated by imagination. Common-sense: one should always be controlled by the facts of the case ascertained by the most careful study, and set forth fairly to both sides. And imagination should try to make the facts living and interesting—not romantic nor sensational, but human."