Sampson County is a county located in the U.S. state of North Carolina. As of the 2020 census, the population was 59,036. Its county seat is Clinton. Sampson County was established in April 1784 following the American Revolutionary War. The North Carolina General Assembly annexed land from the neighboring Duplin County. The neighboring …Sampson County is a county located in the U.S. state of North Carolina. As of the 2020 census, the population was 59,036. Its county seat is Clinton. Sampson County was established in April 1784 following the American Revolutionary War. The North Carolina General Assembly annexed land from the neighboring Duplin County. The neighboring Wayne County and New Hanover counties would be annexed later.