Barbara Rosenkrantz started her teaching career at Harvard as a lecturer in the History of Science Department in 1971. Professor Rosenkrantz was chair of the History of Science Department at Harvard from 1984-1989, and continued to teach at Harvard until her retirement in 1993. 

Following her retirement, Professor Rosenkrantz traveled widely for both pleasure and intellectual growth, and continued to lecture and participate in academic endeavors. 

Professor Rosenkrantz’s scholarly contributions were vast, beginning with her groundbreaking book Public Health and the State first published in 1972. This work was among the first serious investigations of the ideas that animated public health professionals in the 19th and 20th centuries and effectively defined the now-burgeoning field of public health history. Professor Rosenkrantz' s work emphasized the role of the evolving idea of the state in protecting and preventing disease among populations. This focus distinguished public health from medical history that emphasized the development of therapeutic techniques and treatment modalities among individual patients.
 

Throughout her career Professor Rosenkrantz identified the questions of individual and public responsibility for illness, the changing notions of worthiness as criteria for establishing public and private services, and shifting definitions of individual susceptibility as explanations for illness.  Recent concerns about HIV record keeping, surveillance practices in light of the outbreaks of SARS, and, in the U.S., anthrax, demonstrate that the questions Rosenkrantz raised about the limits of public health are still very much in the forefront of modern-day concerns.