Ashley Montagu (1905-1999), physical anthropologist, was a prominent figure in American intellectual life. British by birth, educated at University College London and the London School of Economics, then Columbia University in New York City, Montagu was a persistent advocate for gender and racial equality. He was a tireless activist for human understanding and child welfare in particular. Departing from academe in 1955, a victim of McCarthyite hysteria, he was a remarkably prolific writer and speaker, eventually publishing more than 50 books, over 40 of them after he left the academy. Montagu continued to lobby passionately against the primacy of race in discussions of intellect and skill, and undertook works in a wide variety of fields, from evolution to parenting. Some of his most significant works include Man's Most Dangerous Myth: The Fallacy of Race (1942), the UNESCO Statement on Race (1951), Man and Aggression (1968) and his novel The Elephant Man (1971), which became the basis for an award winning play and movie. Ashley Montagu's contributions to the spread of scientific knowledge and human understanding make him one of the most important intellectuals of the 20th century.

Victor George Heiser, who was a preeminent public health physician, created a rich archive of material documenting all phases of his career, especially the international health work of the Rockefeller Foundation from 1915-1934. There are voluminous, detailed, and interesting diaries for the whole course of his adult life (1890-1972). There are notebooks reflecting on his early training and work (1890-1907), and lectures he attended at Jefferson Medical College in Philadelphia (1897).

The physicist W.F.G. Swann was a pioneer in high energy physics and the study of cosmic rays. Climbing the academic ranks from the University of Sheffield to the Universities of Minnesota, Chicago, and Yale, Swann was selected as the first director of the Bartol Research Foundation of the Franklin Institute in 1927, and remained there until his retirement in 1959. An able administrator and excellent mentor, he was best known for his popular work on the new physics, The Architecture of the Universe (1934) and for his research on cosmic rays. Avocationally, he was an accomplished cellist and in addition to performing, he helped organize and support the Swarthmore Symphony Orchestra and other local groups. He died at his home in Swarthmore in 1962. The Swann Papers consist of 41 linear feet of correspondence, class notes, lectures, and photographs documenting Swann's career at the Bartol Research Foundation from 1927 until the end of his life. The collection is wide ranging, touching on atmospheric electricity, particle acceleration, atomic bomb defense, atomic energy, electrets, electrodynamics, magnetism, music, quantum theory, radiation, relativity and Einstein, science and civilization, stratospheric flights (by balloon and airplane), thermodynamics, psychic science, and wave mechanics. It is particularly rich for study of the history of cosmic ray research and the Bartol Institute, and for study of the popularization of modern physical sciences.

Primary source materials for the history of quantum physics in the twentieth century, collected under the auspices of the American Philosophical Society and the American Physical Society, with a grant from the National Science Foundation.

Though the Miscellaneous Manuscripts collection is composed of items that do not fall readily into any other existing collection, the two dominant intellectual areas represented in the collection are Early American History and History of Science.