Spears were issued to the troops to be used in the event of a British attack.

From 1776 by David McCulough. Page 60.

With the days growing shorter and colder, flocks of wild geese overhead grew in such numbers that orders had to be posted to keep the men from firing at them and wasting precious powder. “Every officer that stands an idle spectator, and sees such a wanton waste of powder, and doesn’t do his utmost to suppress the evil, may expect to be reported,” declared Nathanael Greene.

So great was the need to conserve powder that the morning gun, a camp ritual, was dispensed with. Spears were issued to the troops to be used in the event of a British attack.

Every colonel or commanding officer of a regiment [read another of Greene’s orders] to appoint thirty men that are active, bold, and resolute to use the spears in the defense of the lines instead of guns.