Donna Gerstle Smith worked for the National Park Service for almost three decades as a park ranger and park historian. Her fascination with history began while researching for her ...view moreDonna Gerstle Smith worked for the National Park Service for almost three decades as a park ranger and park historian. Her fascination with history began while researching for her master's degree thesis on nineteenth-century medicine at frontier military posts. Inspired by reading old letters, journals, army medical records and other primary source materials, she found them to be priceless windows for looking into the past.view less