The Neil family papers comprise 87 letters, 26 receipts, 17 financial records, 9 legal documents, 3 printed items, and 2 speeches, spanning 1774-1872. Early correspondence and records document trading and business activities, especially between William Neil and George Andrews. In particular, letters and bills of lading provide much detail on prices, quantities, and types of items purchased by the Neils and other local merchants (including Quaker merchant Abraham Barker). Several additional letters refer to health problems suffered by Margaret Neil, for which she was repeatedly bled (June 8, 1802).
A series of 1814 letters, written by Andrews to William Neil, concerns the War of 1812, including the merchants' preparations for attacks by the British and the effects of war on the market (August 6, 1814: "Business I believe is dull every where…. I am afraid to purchase Goods."). Also present are letters concerning a settlement for losses suffered by the Neils when the schooner John was captured by the British in 1815. A letter of March 28, 1831, recounts the circumstances of the capture and the case for restitution. Approximately five letters and documents dating to 1825, the year of William Neil's death, relate to his estate and the dispersal of his property.
Approximately 30 letters postdate 1830, most of which are the incoming correspondence of Thomas Neil. These primarily concern family news from various relatives, health issues, and details of business transactions. A letter to Maria Neil from her young granddaughter mentions "Emily has been working in the factory but is now going to school" (December 14, 1848). In an unusual and witty letter to Thomas Neil, a 20-year old named "Dorothy" requested his help in finding a husband and provided a humorous description of the man she wanted to find, including his height, the characteristics of his nose, and her preference that he oppose slavery (April 2, 1849).
The collection also includes 21 items relating to the ship Judah Touro and its journey from Boston to Portsmouth in January and February, 1861. These are receipts, records of payments, and several partial inventories.
The Maps series contains one map, entitled Plan of the town of Belfast from actual survey.