1. The title of this document is “Memoir relatif à la construction des batteries qu’on Se propose d’elever pour La deffense de Newyork.”

The Military Committee of New York City consisted of Aaron Burr, H, and Ebenezer Stevens. See “Call for a Meeting,” June 4, 1798, note 2. See also theintroductory note to H to James McHenry, June 1, 1798.

In 1795 Mangin, an engineer born in France, succeeded his superior, Charles Vincent, as engineer-in-chief of the fortifications of the port and harbor of New York. On May 9, 1796, Mangin was “admitted & sworn a Free Man of … [New York] City” and on May 18, 1796, was appointed “a Surveyor of this City” (Minutes of the Common Council description begins Minutes of the Common Council of the City of New York, 1784–1831 (New York, 1917). description ends , II, 236, 238). For Mangin’s citizenship, see also the MS Minutes of the New York Supreme Court, under the date of May 7, 1796, January 19–November 5, 1796 (Hall of Records, New York City). On June 18, 1798, Ebenezer Stevens appointed Mangin to work with John Hills and George Fleming to draw up plans for fortifying the harbor of New York. These plans were completed on August 10, and on September 11, 1798, Stevens placed Mangin in charge of completing the fortification of Fort Jay on Governors Island (Stevens to H, February 28, April 4, 1799). Mangin was also the architect for several important buildings erected in New York City in the late seventeen-nineties and with John McComb, Jr., won a competition in 1802 for the plans for New York City Hall.

2. In the remainder of this document Mangin discusses in detail the measures he proposes for the defense of New York City.