Collin MacGregor (died 1801), known as Coll MacGregor, was a Scottish New York City merchant acting on behalf of Loyalist or British businessmen in Nova Scotia, Great Britain and elsewhere. The collection consists of letterbooks dated 1783-1784, 1786-1789, and 1793-1794 (six volumes); and a priced inventory of goods shipped to and by MacGregor, 1785 (one volume). The letterbook for 1783-1784 includes accounts for 1782-1783, and a ledger sheet for 1791-1792 is also present. Letters are written chiefly to his principal clients, dated predominantly as follows: John Mackenzie, 1783-1784; Neil Jamieson, 1786-1789; and James R. Miller (Miller, Hart & Co.), 1793-1794. He also acted for Shedden, Patrick & Co. Business dealings include an early dry goods venture in Albany, management of investments and debt collection, land speculation in New York State, and disposal of cargoes, including tobacco from his clients' businesses in Virginia. Legal consultations with Alexander Hamilton and the financial affairs of Robert Morris are sometimes noted. MacGregor's letters also describe the impact of political affairs on business, from the aftermath of the British Evacuation of 1783 to the U.S. Constitution, 1787-1789, and the embargo of 1794. A few pages are missing from the letterbooks.