As an adult, Clinton soon distinguished himself in governmental and military service, serving as Duplin County's Register of Deeds for ten years. He was elected to the Provincial Congress held at Hillsboro. In 1776, at the outbreak of the Revolution, Clinton organized a company of militia from upper Duplin County and led them as captain in the defense of Wilmington against the British. He was later appointed Colonel of Cavalry and Brigadier General of the Fayetteville District. Upon the establishment of the state government of North Carolina by the Halifax Constitution of 1776, Clinton was elected as one of the first members of the House of Commons, representing the County of Duplin as a House member. Clinton continued as a representative of Duplin County until the creation of Sampson County in 1784. Clinton secured passage of the act creating the new county, and proposed the name "Sampson" in honor of John Sampson, his stepfather and benefactor.