John J. McCloy served as Assistant Secretary of War from 1941 to 1945. The diaries are largely day to day records of McCloy’s activities, with some narrative containing his impressions of individuals and events.
Topics of particular interest include: the Japanese-American relocation program (1941 and 1942); McCloy’s tour of North Africa (1943 Feb-Mar) and Italy (1943 Dec); the Cairo Conference (1943 Nov-Dec); planning for post-war Germany (1944-1945); the Normandy invasion (1944 Apr-Jun); McCloy’s tour of the front, the death of President Roosevelt and plans for war crimes trials (all 1945 Apr); various issues relating to the atomic bomb (1945 May-Nov); the Big Three Conference in Berlin (1945 Jul); the Japanese surrender and the end of the war (1945 Aug); and McCloy’s ensuing world tour (1945 Sep-Nov).
Full finding aid for the John J. McCloy (AC 1916) Papers, 1897-1989: http://asteria.fivecolleges.edu/findaids/amherst/ma35.html.
PDFs of John J. McCloy World War II Diaries: