In September 1775, early in the American Revolutionary War, Colonel Benedict Arnold led a force of 1,100 Continental Army troops on an expedition from Cambridge in the Province of Massachusetts Bay to the gates of Quebec City. The expedition was part of a two-pronged invasion of the British Province of Quebec, and passed through the wilderness of what is now Maine. The other expedition invaded Quebec from Lake Champlain, led by Richard Montgomery.
Unanticipated problems beset the expedition as soon as it left the last significant colonial outposts in Maine. The portages up the Kennebec River proved grueling, and the boats frequently leaked, ruining gunpowder and spoiling food supplies. More than a third of the men turned back before reaching the height of land between the Kennebec and Chaudière rivers. The areas on either side of the height of land were swampy tangles of lakes and streams, and the traversal was made more difficult by bad weather and inaccurate maps. Many of the troops lacked experience handling boats in white water, which led to the destruction of more boats and supplies in the descent to the Saint Lawrence River via the fast-flowing Chaudière.
By the time that Arnold reached the settlements above the Saint Lawrence River in November, his force was reduced to 600 starving men. They had traveled about 350 miles (560 km) through poorly charted wilderness, twice the distance that they had expected to cover. Arnold's troops crossed the Saint Lawrence on November 13 and 14, assisted by the local French-speaking Canadiens, and attempted to put Quebec City under siege. Failing in this, they withdrew to Point-aux-Trembles until Montgomery arrived to lead an unsuccessful attack on the city. Arnold was rewarded for his effort in leading the expedition with a promotion to brigadier general.
Arnold's route through northern Maine has been listed on the National Register of Historic Places as the Arnold Trail to Quebec, and some geographic features in the area bear names of expedition participants.