Each state legislature appointed officers for both county and state militias and their regimental Continental Line officers; although Washington was required to accept Congressional appointments, he was still permitted to choose and command his own generals, such as Nathanael Greene, his chief of artillery, Henry Knox, and Alexander Hamilton, the chief of staff. One of Washington's most successful recruits to general officer was Baron Friedrich Wilhelm von Steuben, a veteran of the Prussian general staff who wrote the Revolutionary War Drill Manual.}} The development of the Continental Army was always a work in progress and Washington used both his regulars and state militia throughout the war; when properly employed, the combination allowed them to overwhelm smaller British forces, as at Concord, Boston, Bennington, and Saratoga. Both sides used partisan warfare, but the state militias effectively suppressed Loyalist activity when British regulars were not in the area.