Some Early American History suggestions in NC, & all have camping within a reasonable distance, I enjoyed all of these:
Lost Colony historic site and outdoor drama - at Roanoke Island, NC
Tryon Palace - at New Bern, NC
Museums of Natural Science, History, and Art - at Raleigh, NC
Old farms, Folk Music+Folk Art+Visitor Centers, Mineral Museum -Blue Ridge Parkway
Mt. Mitchell highest elevation east of the Mississippi-Blue Ridge Parkway
Old Brunswick Towne/Fort Anderson/Orton Plantation - near Wilmington, NC
Fort Fisher - near Kure Beach, NC
Fort Macon - near Atlantic Beach, NC
Fort Caswell - near Oak Island, NC
Cape Lookout Lighthouse and other lighthouses - along the outer banks area NC
Wright Brothers first flight memorial - Nags Head, NC
Biltmore House - Asheville, NC
Great Smokey Mtn Railroad - Bryson City, NC
Old Salem+Bathabra+Bethania, Winston Salem NC
River Lock system on the Cape Fear River - several locations
Battleship NC - Wilmington, NC
Guilford Battleground - Greensboro, NC
not historic, but educational:
NC Zoo - at Asheboro, NC
Three different NC Aquariums, at Roanoke Island, Pine Knoll Shore, and Fort Fisher.
Many more check out
www.visitnc.com
ps: all state parks in NC are free entry