3. Arnold’s expedition was beset by spies and Loyalist sympathizers
Arnold’s maps were provided by a surveyor from Gardinerstown named Samuel Goodwin. Goodwin was a Loyalist, and the maps he provided were misleading. They were prepared with inaccurate distances described between certain points. They omitted or misplaced several important landmarks by which Arnold could ascertain his whereabouts during the advance. They also provided incorrect routes through the swamps which the expedition later encountered. Arnold’s departure from Newburyport was also noted by Loyalist sympathizers, and before the expedition departed up the Kennebec their movement was known by the British, who accurately surmised their destination.
The Bateaux which had been ordered earlier in the summer were not ready in sufficient numbers for the force to depart. Those that were had been constructed of unseasoned wood, and leaked badly. During the movement up the river, leaking boats imperiled the supplies of food and gunpowder carried within. They were also smaller than Arnold had specified in his orders. The expedition was delayed while the needed boats were completed, and the haste with which they were built was reflected in the poor quality of their construction. On September 25, Arnold and the full expedition departed for the settlements furthest up the Kennebec, with some traveling overland and the others with the supplies in the Bateaux.