Secret Weapons: A Tale of the Revolutionary War — Jessica Gunderson

The British are coming! Fourteen-year-old Daniel wants to join the militia and fight against the redcoats. His father wants him to stay in Concord, Massachusetts, and help run the blacksmith shop. Daniel thinks the job is pointless, until he finds a secret stash of weapons in the shop's back room. Now, he must protect the weapons from the British, or the American Revolution could be over before it begins.