The area was first granted on December 31, 1735, by colonial governor Jonathan Belcher of Massachusetts as "Plantation No. 4", the fourth in a line of forts on the Connecticut River border established as trading posts. Settled in 1740, it was the northernmost township, and its 1744 stockade known as Fort at Number 4 became a strategic military site. On the evening of May 2, 1746, Seth Putnam joined Major Josiah Willard and several soldiers as they escorted women to milk the cows. As they approached the barn, Natives hiding in the bushes opened fire, killing Putnam, "the first victim of vengeance". In 1747, during King George's War, the fort was besieged for three days by a force of French and Native people. Captain Phineas Stevens and 31 soldiers stationed at the fort repelled the attack, with their success becoming well-known.