The Henry Lewis Stimson diaries, spanning the years 1909-1945, cover a long public career and offer scholars an invaluable historical source. Stimson began keeping the diaries in 1909 when he was forty-two years old. Characteristically, he made a conscious decision at that time to keep a full record of his public life, and the diary was maintained down to his last day in public office on September 21, 1945.

The diaries are full of views on people, issues, and events. As a political document and as a political testament, the diaries stand as a significant personal account of the career of an American statesman of the first rank.