Abstract This collection encompasses most of Delbrück's lifetime and chronicles his role in the development of molecular biology. The bulk of the materials date from the time of his immigration to the U.S. in 1946. They include personal and professional correspondence, lectures, manuscripts, and biographical material. These materials relate to topics such as his immigration as a German scientist during the early years of World War II; biophysics; his work with the Phage Information Service; his...