In June of 1779, the British set up a fort at Castine. Hearing of this, the Continental Congress sent a strong expedition to drive the British out, with some forty ships and 1,000 men. Arriving in late July, the Americans lay siege to the British instead of attacking. This delay was costly, for by the time the Americans decided to attack from the sea, they were confronted by a British relief fleet. The Americans fled up the river, destroying all of their shipping, with over 400 men killed, wounded, or captured. This was considered to be the worst American naval defeat until Pearl Harbor. Commodore Dudley Saltonstall was blamed and dismissed from service. Paul Revere was court martialed but acquitted.