Tne Manhattan Project



Vannevar Bush


March 9, 1942.

The President,

The White House

Washington, D.C.

Dear Mr. President:

On October 9, 1941, Mr. Wallace and I presented to you the status of research in this country and Great Britain, on a possible powerful explosive.

In accordance with your instructions, I have since expedited this work in every way possible. I now attach a brief summary report of the status of the matter.

Considerations of general policy and of international relations have been limited for the present to a group consisting of Mr. Wallace, Secretary Stimson, General Marshall, Dr. Conant, and myself. Mr. Wallace has called a conference of this group, to which he invited also Mr. Harold D. Smith as the matter of funds there was considered.

The technical aspects are in the hands of a group of notable physicists, chemists, and engineers, as noted in this report. The corresponding British organization is also indicated. The work is under way at full speed.

Recent developments indicate, briefly, that the subject is more important than I believed when I last spoke to you about it. The stuff will apparently be more powerful than we thought, the amount necessary appears to be less, the possibilities of actual production appear more certain. The way to full accomplishment is still exceedingly difficult, and the time schedule on this remains unchanged. We may be engaged in a race toward realization; but, if so, I have no indication of the status of the enemy program, and have taken no definite steps toward finding out.

The subject is rapidly approaching the pilot plant stage. I believe that, by next summer, the most promising methods can be selected, and production plants started. At that time I believe the whole matter should be turned over to the War Department.
You returned to me the previous reports, in order that I might hold them subject to your call. I shall be glad to guard this report also if you wish.

Respectfully yours,

V. Bush, Director

The Manhattan Project: The Birth of the Atomic Bomb in the Words of Its Creators, Eyewitnesses, and Historians, edited by Cynthia C. Kelly, Black Dog & Leventhal Publishers, Inc., 2007.

Photograph: E. O. Lawrence, A. H. Compton, V. Bush, J. B. Conant, K. Compton, and A. Loomis in March 1940 at a UC Berkeley meeting.