This lecture will look at the development of an archive that was unique in its time: The ‘Sources for the History of Quantum Physics’. Funded by the National Science Foundation, the project started in 1961 with the aim to document the formative times of quantum physics in the 1920s and 1930s. Apart from collecting manuscripts and notebooks, the main task of the three historians who were involved in the project, Thomas Kuhn, John Heilbron and Paul Forman, was to interview the ‚living sources’ that remembered the main steps in development of modern physics. However, by collecting hundreds of oral histories from famous physicists, the project group became more and more conscious of the fallacies of oral history. What were the expectations?