Little Boy was assembled on Tinian on July 31. The bomb could in theory be dropped the next day. However a typhoon was moving towards Japan and weather would delay the bomb drop for several days. Secretary of War Henry Stimson sent to Harry Truman a proposed statement to be released after the bomb drop:
Letter of Statement Draft
From: Henry Stimson, Secretary of War
To: Harry S Truman, President of the United States of America
Date: July 31, 1945
July 31, 1945
Dear Mr. President:
Attached are two copies of the revised statement which has been prepared for release by you as soon as the new weapon is used. This is the statement about which I cabled you last night.
The reason for the haste is that I was informed only yesterday that, weather permitting, it is likely that the weapon will be used as early as August 1st, Pacific Ocean Time, which as you know is a good many hours ahead of Washington time.
This message and inclosure are being brought to you by Lt. R. G. Arneson, whom Secretary Byrnes will recognize as the Secretary of the Interim Committee, appointed with your approval, to study various features of the development and use of the atomic bomb.
Secretary of War. (more…)