Series I, General Correspondence and Official Papers is divided into four subseries. Incoming Letters received by Pratt are arranged alphabetically by author and chronologically within each folder. A folder of unidentified material is placed at the end of this section. Outgoing Letters written by Pratt are arranged chronologically. Pratt's letters from the years 1872 to 1904 are bound in 60 volumes of letterpress copies. Additional unbound letters from these years, as well as the letters from 1904 until Pratt's death in 1924, are arranged chronologically in folders. Letters of Others, found with Pratt's or Pratt's family's correspondence, but which are not to or from Pratt are arranged alphabetically by author. Official Papers is a file of material relating to Pratt's early Army career, his command of Indian prisoners in Florida, the beginnings of the Carlisle Indian Industrial School, and other Army related matters. Reports, orders, official correspondence and communications are contained in this section. This file contains material both to and from Pratt as well as communications of others. The material in this file is arranged chronologically. Note: Individuals represented in Official Papers may also be represented in other subseries of General Correspondence.