The contents of this collection are housed within one box. Each letter is housed within its own folder which has been labeled with the date of the letter. Envelopes in which the letters were mailed and other accompanying enclosures are included inside the corresponding folders. Each folder is arranged in ascending order by date.
Three letters appear to have been dated incorrectly by Arnold stating the year to be 1863 instead of 1864. These letters are in the folders 1/24/1864, 2/12/1864, and 3/1/1864. One folder is labeled 8/?/1865 because Arnold did not record the exact date of the letter. The folder 1/24/1864 contains two letters marked with same date.