He was called upon to raise a militia company of men in New Hanover County to protect against any Spanish raids or invasions from Florida.
In 1771, Sampson served as a Lieutenant General in the Colonial Militia of the Royal Governor William Tryon, fighting against members of the Regulator Rebellion in Halifax, North Carolina.
There was widespread fighting and civil disobedience: county justices of the peace, such as future state governor Alexander Martin, were attacked and flogged on the street by Regulators.
Governor Tryon led an attack in what became known as the Battle of Alamance, which resulted in between 8-12 men killed and as many as 100 wounded.
He is believed to have continued in this role after the Halifax Constitution of 1776 was signed and Richard Caswell became Governor of the state.