Ranging from his earliest mercantile activities to his last days in debtors' prison, these letters to and from Duer contain a wealth of information pertaining to his financial career. They include, among other topics, descriptions of the work being done at Fort Miller and the Poughkeepsie distillery, Duer's contracts to supply military troops, and land and stock speculation including letters regarding the Scioto company. The papers also include a few letters dealing with Duer's work in public service. There is also a family tree of the English Duers compiled in 1895.

The correspondence is arranged in chronological order and is available on microfilm.

This series contains letters between Tench Tilghman, aide-de-camp to General Washington, and the Committee of Correspondence of the New York State Convention. The purpose of the Committee was to obtain and communicate war intelligence. Duer was a member of this Committee and was the primary writer of letters to Tilghman. The letters from Tilghman contain comprehensive reports on the status of the American troops, the British troops and the progress of the war. Duer's letters contain questions and observations as well as advice on the war. Note: The letters are 1881 copies of 1776 transcripts.

These letters deal with family matters and Duer's financial situation.

The majority of the correspondence of Duer's son, William Alexander Duer, consists of letters to Hugh Peebles about his financial affairs. The one letter not addressed to Peebles is to John Rutherfurd concerning a speech Duer was to give at the New-York Historical Society on federal and state constitutions.

The bulk of these cases were heard in the chancery court of New York during the 1790s. Also included are a few cases from other states. In the majority of cases the direct relationship to Duer is unclear. The New York cases were presided over by Chancellor Robert B. Livingston, Esq. All cases in the collection are incomplete; materials are arranged alphabetically by plaintiff.

This series consists of legal documents relating to Duer, his business associates, and others. The papers include contracts, agreements and indentures, as well as summons, affidavits, court opinions and other documents. They are arranged in chronological order.

Duer was held in debtors' prison from 1792 until his death in 1799. In order to preserve order and harmony there, some of the prisoners established a "court" to hear disputes between prisoners. Certain prisoners were elected "judges." Duer was elected a "judge" in 1797. These papers consist of documents of that court, including the facts in various cases, judgments rendered, court attendance records, and records of the elections of the court officers.

The series includes bills, receipts, notes and other documents pertaining to Duer's Poughkeepsie Distillery.

The series contains records of debts owed by and to Duer as well as third-party debt. Deeds and leases pertaining to Duer and others are also included. An earlier inventory noted that Box 6, folder 5, has been microfilmed on reel 4-44, but no such folder is found on the microfilm.

The series includes invoices from the entire spectrum of Duer's mercantile involvement.

The series includes accounts, expenditures and other records from Fort Miller, where Robert Snell, an early business associate of Duer's, managed the mercantile activities and lumber mill work. Also included are Duer's papers concerning the debt Snell had incurred while managing Duer's day-to-day business affairs.

The series includes invoices and other documents relating to Duer's lumber operation, especially the production of ship masts.

The documents in this series involve Duer's siblings. A family tree, wills, information on the family's plantations in the Caribbean, legal papers and other documents are included. The materials are out of chronological order but mirror their order in the microfilmed version.

The series includes financial documents pertaining, for the most part, to Duer's involvement in land, stock, bank notes, and other areas of eighteenth century speculation.

The series contain records and receipts from Duer's contracts to supply divisions of the American army with food and other necessities during and after the Revolutionary War.

The series includes records from various accounts and an account book from Duer's mercantile enterprises. Materials are arranged by name and in approximate chronological order.

The series includes bills, receipts and notes.

The series includes materials not assigned to other series at the time that the collection was microfilmed, including "…Arrangement to be Made of Mr. Duer's Papers"; "Inventory of Sundry Merchandise Remaining in the Store at Fort Miller on the 13th day of December 1773"; "an Account of Cash Received in the Store at Fort Miller," not dated; an advertisement dated 1766 that announces an upcoming survey; an undated plan for a paper mill; three items related to the donation of a canopy for a lodge in New Jersey, dated 1792 and 1793. Nineteenth century items include two indentures involving W.A. Duer (1807 and 1810) and several pieces of correspondence as well as a listing of items included in the bound volumes (see Series XIX).

The two volumes of correspondence include letters received by Duer related mostly to supplying the American Army during the Revolution, the Scioto Land Company, and the settlement of Illinois. They are numbered in pencil from 1-138 (volume 1) and 139-257 (volume 2). The timber contracts pertain to agreements with the governments of Spain and France to supply timber for ship masts and spars. Silas Deane, James Wilson, and Mark Bird were also associated with this enterprise. The remainder of this volume appears to have been used for penmanship practice and casual use.

Volumes 1 and 2 are available on reel 3 of the microfilm.