Upon arriving at Boston, Washington believed he had 20,000 troops but quickly learned that he actually had less than 15,000. Additionally, he was desperately low on supplies and gunpowder. Immediately he realized the dangerous situation he was in. Thus, he began assembling his team of generals from the thin colonial ranks, appointing Horatio Gates, Charles Lee, Israel Putnam, Philip Schuyler, and Artemis Ward as his senior officers. After establishing his headquarters in Cambridge, he now turned his attention to the siege that was occurring in Boston.
The British had started its siege after the battles of Lexington and Concord earlier that year in April. In subsequent the subsequent Battle of Bunker Hill in June, the colonists were able to inflict a heavy casualties in a British Pyrrhic victory, boosting patriot morale. Washington’s presence also gave the troops a much-needed emotional lift. Still, Washington began to mold his undisciplined army into some semblance of a fighting machine. He ordered that his offers wore special attire to distinguish them from the rest of the troops, introducing much-needed hierarchy to the army. He ordered the building of trenches and fortifications to enhance his defensive posture. Also, Washington sought to inculcate discipline and virtuous conduct among his troops, sending out general orders that discouraged drunkenness and other vices and encouraged the attendance of religious services. Washington was also not afraid to mete out punishment for bad behavior.
Soon, companies of riflemen arrived from Maryland, Pennsylvania, and Virginia.