Incoming correspondence to George Engelmann from Charles Sprague Sargent, for 1874-1877. The correspondence relates to the collaboration and interchange of information, mostly on trees in which Engelmann specialized. Engelmann's assistance in Sargent's work as an expert and special agent in the 1880 census. (1879-1882); Sargent and Engelmann's trip to California in the summer of 1880, their itineraries and discoveries, follow-up studies and discussions. Disposition of Engelmann's microscopic wood specimen slides and Engelmann's tree measurement data. Discussion of drawings and photographs for publication of the North American trees. Routes of Sargent's various trips.

Folder contains original letters.