The collection consists of two notebooks, one of which contains copies of letters written to his wife describing the cruelties, the intolerable conditions and the brutality of guards. He also wrote letters to Ludyah Robinson, esq, May 27-30, 1832. There are copies of letters to Mrs. Hosmer from Asa M. and from Stanford Robinson, June 3, 1882, who told her of her son's death; and a letter from James Price to Ludyah Robinson, May 30,1822.

The second notebook contains "a partial history" of the final days of Asa Hosmer and his son, Asa M., based on letters received by his wife and daughter, Sophia Robinson. This account was written by a 20th century descendant and covers the period from 1816 to the 1850s.