Led by Dr. Samuel Adams of Arlington, New Hampshire Grants (now Vermont), the Rangers made their most significant contribution to the British war effort by serving with the ill-fated Burgoyne Expedition in the Saratoga campaign of 1777.

Either late in the Burgoyne campaign or in early 1778, the Rangers absorbed a body of soldiers from the Bateaux Service, under Jeptha Hawley, who was also from Arlington.

After the British Army's defeat and surrender at Saratoga, Adams' Rangers and other Loyalist units were allowed to retreat to the Province of Quebec.

For the next three years Adams' men, like most other Loyalist troops in Canada, were occupied with garrison duty and employed in work parties improving the defences of the Province.

In November 1781, these British units were consolidated into a new Provincial regiment, the Loyal Rangers, commanded by Major Edward Jessup.