With the British Army in firm control of the city of Boston, Washington knows it is important to keep it bottled there, unable to attack the surrounding areas. He continues the process of fortifying the nearby strong points in Cambridge, Dorchester, and other areas. To do so, he relies on large companies of soldiers on fatigue duty: performing duties not related to fighting, such as digging trenches and building fortifications. For Washington to succeed, he needs the expertise of engineers like Captain Jeduthan Baldwin of Brookfield.