This pen-and-ink and watercolor manuscript map made by engineers of the French Army shows the city and harbor of Portsmouth, New Hampshire, as they appeared in the early 1780s. The map shows part of the fleet of Admiral Charles Louis de Ternay, which brought General Rochambeau and 6,000 troops from France to fight with the Continental Army during the Revolutionary War in the United States. The fleet reached Portsmouth on July 10, 1780. The map centers on the Piscataqua River that flows through Portsmouth to the Atlantic Ocean. It shows abandoned American batteries, forts, new batteries to protect the French fleet, ship anchorages, soundings, a local hospital, and other sites of military significance. It also indicates ferry crossings and the roads to Penobscot (in present-day Maine) and Newbury, Massachusetts. Newcastle Island, located prominently in the center of the map, later became a suburb of Portsmouth. It was the site of the Wentworth Hotel where, during the Portsmouth Peace Conference of 1905, the Russian and Japanese delegations negotiating to end the Russo-Japanese War stayed and ultimately signed an armistice. Scale is indicated in toises, an old unit measuring almost two meters. Relief is represented by hachures. The map is from the Rochambeau Collection at the Library of Congress, which consists of 40 manuscript maps, 26 printed maps, and a manuscript atlas that belonged to Jean-Baptiste-Donatien de Vimeur, comte de Rochambeau (1725‒1807), commander in chief of the French expeditionary army (1780‒82) during the American Revolution. Some of the maps were used by Rochambeau during the war. Dating from 1717 to 1795, the maps cover much of eastern North America, from Newfoundland and Labrador in the north to Haiti in the south. The collection includes maps of cities, maps showing Revolutionary War battles and military campaigns, and early state maps from the 1790s.