The collection consists of 19 pieces of manuscript poetry, 5 letters, and a repurposed Canadian almanac that has 18 of Mary Middlemore's published pieces tipped in, as well as an additional 6 loose pieces (two of which are prose, the rest poetry, three of which appear to be duplicates of hand letterpress printed poems).
The majority of the material was written by Mary Manks Middlemore, with her name as 'Mrs. R. Middlemore' on a letterpress label identifying the collection as being her original poetry, except for a few of these poems labelled 'not mine', including one attributed to Mary Middlemore, presumably her niece and eventually daughter-in-law. The manuscript material may also contain poems by the junior, and possibly Thomas as well, though the majority seems to be from the elder Mary. While largely undated, the material seems entirely to have been written in Canada from the 1840s through the 1870s.
The group of five letters, 1834-1843, are addressed to Squire Manks of New Brunswick, the senior Mary's elder brother, and date from the period prior to the family's move to Canada. The letters include contributions by Robert Middlemore, the elder Mary, as well as the younger Mary, sometimes with multiple writers per letter. They provide background family details, and often discuss the possibility of emigration. In addition to the letters, the archive includes the marriage certificate of Thomas Middlemore and Mary Manks from 1849, a lock of the senior Mary's hair from 1880, and a card with the burial details of both Thomas and Mary Middlemore from the 1880s.
