The letters are arranged alphabetically under the headings: seventeenth century (folio 1), early eighteenth century (folio 85), Lord Milton and family (folio 131), General John Fletcher (folio 257), nineteenth century (folio 295), and twentieth century (folio 325).

Several undated letters, have been left under the year where they were found, in the hope that this represents their original position; but the many certain errors in arrangement which had to be corrected reduce the chances of this.