The Nathaniel Peaslee Sargent Papers contain the judge's court notes in pamphlet-type notebooks and loose papers, letters, orders, Grand Jury charges, receipts, land surveys and related documents, verdicts, wills, accounts, and personal writings on the history of Haverhill and the American Revolution. These records are all original to the time period of his life and slightly after. The second group of records in this collection is from a later period. They are mostly copies of original records of Sargent's and research material for an included, draft manuscript on his life, circa 1931. This collection has been organized into three series.

Series I. Court Minutes contains pamphlet-style notebooks, larger, bound notebooks, and loose papers that contain Judge Sargent's notes on the proceedings of courts that he presided over during his time as both an Associate Justice and a Supreme Justice of the Massachusetts Supreme Court.

Series II. Correspondence and Legal Papers contains mostly letters and receipts of Judge Sargent's. There are also original orders he sent out for individuals to appear in court, official documentation of charges to be delivered to individuals facing them, and verdicts that he passed down on individuals appearing before the various court sessions he held. There are some personal writings of Judge Sargent as well. These consist of four documents chronicling the history of the city of Haverhill, a short treatise reflecting on the American Revolution, through which he lived and worked, and other assorted writings. A copy of multiple wills for some individuals, alongside a copy of Sargent's own will and supporting documents are also contained in this series. There are also two surveys of his property and lists of his material items and writings as well.

Series III. Research Materials and Manuscript on Nathaniel Peaslee Sargent contains research materials that Judge Ira A. Abbott used to help in the creation of his article on Sargent's life, Life and Times of Judge Sargent. His materials range from multiple correspondence, tracing lineage and facts about the Judge, to notes on certain individuals and areas important to Sargent's life. Folder 9 in box 3 contains copies of various documents from the first two series. There are also copies of records that do not appear in this collection in original form. It seems that the originals for this collection of copies may have existed in the Massachusetts Archives or American Antiquarian Society's collection, but it is not clear. There are also photographs of Judge Sargent's home and his family grave plot that are marked "illustration" and may have been used for the Life and Times article, but this is unclear as well.

The last folder in this series (B3 F12) contains the draft manuscript in full. It appears that it was published in the Haverhill Sunday Record, April 23 to August 13, 1933, under an edited name, Life and Times of Judge Sargeant: Being a Biography of Nathaniel Peaslee Sargeant of Haverhill, Mass., Second Chief Justice of the Supreme Judicial Court of Massachusetts.