Travel in Europe – correspondence, itineraries, and photograph lists, 1966

Series IV primarily relates to Kellogg's publications; it includes his sent and received correspondence with publishers and comments and requests from fellow scientists. Most of the remainder of the correspondence is with other United States Department of Agriculture (USDA), Soil Survey, and Extension Service officials and scientists. It concerns work-related subjects such as soil erosion, the development of a new soil classification system, and travel arrangements. This series is arranged chronologically.