The Einstein letter together with FDR’s reply is found in Vincent C. Jones,

Manhattan: The Army and the Atomic Bomb (US Government Printing Office, 1985). A good introduction to the Einstein story, taking into account all the latest discoveries of letters and organized in a conventional chronological format, is Walter Isaacson,

Einstein: His Life and Universe (Simon and Schuster, 2007). For details on the German research effort, see Richard Rhodes,

The Making of the Atomic Bomb (Simon and Schuster, 1986); McGeorge Bundy,

Danger and Survival: Choices about the Bomb in the First Fifty Years (Random House, 1988); Mark Walker,

German National Socialism and the Quest for Nuclear Power, 1939-1949 (Cambridge University

Spying on the Bomb: American Nuclear Intelligence from Nazi Germany to Iran and North Korea (Norton, 2006). The best introduction to the making of the atomic bomb is still Henry D. Smyth,

A General Account of the Development of Methods of Using Atomic Energy for Military Purposes under the Auspices of the United States Government, 1940-1945 (US Government Printing Office, 1945).

For the role of the atomic scientists, see Robert Jungk,

Brighter Than a Thousand Suns: The Moral and Political History of the Atomic Scientists (Victor Gollancz, 1958); Robert Gilpin,

Unknown page