Although few of McDowell's own letters are present, he received many from friends. For instance, Congressman James Breckinridge kept him informed on national banking and foreign affairs both before and after the War of 1812; his agents in Ohio, Nathaniel Pope and W.A. Trimble, and his agent in Kentucky, Nathaniel Hart, wrote him of conditions in those states; and letters from John H. Peyton, Francis Preston, and Jonn Preston discuss business and politics in Virginia.
In addition, the papers contain a complete inventory of his estate, 1835, including the age and reputed value of each of his forty-one slaves; and an 1824 manuscript plat map of Pattonsburg, Virginia. In three volumes McDowell recorded sales of produce, livestock, and whiskey from his plantations; and the sale of internal revenue stamps, 1796-1801.
