Coordinates: 43°15′18″N 72°25′56″W / 43.25500°N 72.43222°W The Fort at Number 4 was the northernmost British settlement along the Connecticut River in New Hampshire until after the French and Indian War. Now known as Charlestown, it was more than 30 miles (50 km) from the nearest other British settlement at Fort Dummer. Construction began in 1740 by brothers Stephen, Samuel and David Farnsworth. By 1743, there were 10 families settled in a square of interconnected houses, enclosed in a with a guard tower.
In 1744, during King George's War, many of the area's outlying farms and buildings were burned by the French and their Indian allies. Some settlers, along with some Indian warriors, were killed in ambushes and small skirmishes. Other settlers were taken prisoner, to be ransomed back in Canada. The settler families would abandon the fort in the fall of 1746, and it was then occupied by Capt. Phineas Stevens and 30 militia troops in the spring of 1747. On April 7, 11 days after Capt. Stevens and his men arrived, the fort was besieged by a large force combining French militia and Abenaki warriors (said be 700 strong, although probably much less), under the command of Ensign Boucher de Niverville of the French Marines. The siege lasted 3 days, until the French and Indians decided to head back to Canada rather than risk a direct attack on the fort, thus preventing further raids on settlements to the south and east.