In Winter 1777-1778, in Valley forge there was no actual battle fought. But they had very limited supplies and harsh temperatures. Many had passed away from malnutrition and disease. Fredrick Von Steuben came and taught them Military skills
In concord the British had found new weapons and the colonists had hid them. Over 100 colonists had been killed or wounded and the Colonists responded with anger.
Bunker hill was a battle between the British and the Colonists and it used to scare the British. They needed Cannons and good Weapons.