After months of alarm and gathering of resources, on July 19, 1779 forty vessels left Boston Harbor for Penobscot Bay on the ill-fated Penobscot Expedition to remove the British from that region and Castine in particular. Not willing to await regular military forces, the group was composed of volunteers, amateur soldiers, and privateers hoping for a share of spoils from the to be defeated British.
On July 25th, the expedition arrived and anchored off Bagaduce (Castine) seeking a favorable opportunity to engage the enemy and land troops. On July 28th, the nineteen armed ships and twenty-four transports met a disastrous defeat on the Penobscot River at Bangor while attempting to escape a badly planned, now confusing, situation. American ships fled up the river but were trapped and destroyed. Peleg Wadsworth was in command of the forces that landed on the peninsula of Castine.
Commodore Dudley Saltonstall was court-martialed for his role in the disaster. Paul Revere, the colonel in charge of ordinance for the expedition, was acquitted of charges and returned to silversmithing.