Before dawn on June 6, 1944, as the cruiser Augusta headed toward the coast of Normandy, Chester Hansen was up and, as always, at the side of Gen. Omar N. Bradley. And as always, Mr. Hansen, a journalist by training and a top aide to Bradley, made notes in his diary:

“Like others in the Army party, Bradley was up at 3:30. He is on the bridge, a familiar figure in his ODs with Moberly infantry boots and OD shirt, combat jacket, steel helmet. He smiles lightly as though it is good to be nearer the coast of France and get the invasion under way.”

Mr. Hansen, who died on Oct. 17 at 95, had been assigned to Bradley when he was conducting training in Louisiana and followed him as he rose through the ranks, accompanying him in the North Africa campaign and the invasion of Sicily and as he led American ground forces on D-Day as commander of the First Army....