This accession consists of manuscript files documenting the writings and research of Harrison E. Radford. Radford joined the Smithsonian Astrophysical Observatory (SAO) in 1969, as a physicist in the Radio and Geoastronomy Division, after nearly a decade with the National Bureau of Standards. His work with the Bureau included measurements by microwave spectroscopy of the OH radical at 18 cm that led to its detection at radio wavelengths in the interstellar medium. At SAO, Radford became internationally known for his pioneering laboratory experiments that led to the discovery of complex hydrocarbon molecules in space.