Letter from Albert Einstein to President Franklin Delano Roosevelt about nuclear physicist Dr. Leo Szilard, 1945.

112 Mercer Street
Princeton, New Jersey
March 25, 1945

The Honorable Franklin D. Roosevelt
The President of the United States
The White House
Washington, D.C.

Sir:
I am writing to you to introduce Dr. L[eo]. Szilard who proposes to submit to you certain considerations and recommendations. Unusual circumstances, which I shall describe further below, induce me to take this action in spite of the fact that I do not know the substance of the considerations and recommendations which Dr. Szilard proposes to submit to you.

In the summer of 1939 Dr. Szilard put before me his views concerning the potential importance of uranium for national defense. He was greatly disturbed by the potentialities involved and anxious that the United States Government be advised of them as soon as possible. Dr. Szilard, who is one of the discoverers of the neutron emission of uranium on which all present work on uranium is based, described to me a specific system which he devised and which he thought would make it possible to set up chain reactions in unseparated uranium in the immediate future. Having known him for over twenty years, both for his scientific work and personally, I have much confidence in his judgement and it was on the basis of his judgement as well as my own that I took the liberty to approach you in connection with this subject. You responded to my letter dated August 2, 1939 by the appointment of a committee under the chairmanship of Dr. Briggs and thus started the Government's activity in this field.

The terms of secrecy under which Dr. Szilard is working at present do not permit him to give me information about his work; however, I understand that he now is greatly concerned about the lack of adequate contact between scientists who are doing this work and members of your Cabinet who are responsible for formulating policy. In the circumstances I consider it my duty to give Dr. Szilard this introduction and I wish to express the hope that you will be able to give his presentation of the case your personal attention.

Very truly yours,
(A. Einstein)