Letter from Secretary of War Henry Stimson to President Truman, informing him about the atomic bomb

April 24, 1945
Dear Mr. President,

I think it is very important that I should have a talk with you as soon as possible on a highly secret matter.

I mentioned it to you shortly after you took office but have not urged it since on account of the pressure you have been under. It, however, has such a bearing on our present foreign relations and has such an important effect upon all my thinking in this field that I think you ought to know about it without much further delay.

Faithfully yours,
Henry Stimson
Secretary of War