Rutherford began his extensive military career in 1760 during the French and Indian War. He was a participant in several battles and skirmishes, most notably the Battle of Fort Duquesne (1758); the battle at Fort Dobbs (1760); and James Grant's campaign against the Cherokee in the southern Appalachians (1761). By the war's end, Rutherford had achieved the rank of captain. Between 1769 and 1771, he embraced the cause against the rebels during the Regulator Movement and commanded a local militia that participated in the Battle of Alamance (May 16, 1771). The following month, Rutherford retired to Salem to recover from an acute attack of gout.