He led a failed attempt to capture Fort Cumberland in 1776 and was forced to retreat to Massachusetts, the place of his birth.

In 1755, he enlisted in the Massachusetts militia and participated in Robert Monckton's successful capture of Fort Beauséjour on the Isthmus of Chignecto in the French and Indian War.

Following Governor Francis Legge's crackdown on seditious persons, and seeing an opportunity, Eddy fled to his riding in Cumberland.

[3] He was eventually able to convince the Massachusetts legislature to provide logistical support in the form of small arms (muskets) and other military supplies.

[5] Shortly after General William Howe's army departed Nova Scotia to attack New York in 1776, Eddy made his move.