There's Cedar Point
near Swansboro, NC. 30A electric on site, water spigots every few sites. Nice level, paved sites, boardwalk over the salt marsh, interpretive trails and boat dock are a short walk or bike ride away. Our favorite campground on the NC coast. It is about an 1 1/2 hr from Wilmington but you may be able to make it a stop-over point.
Note, in December the dump station was closed, not sure if it is open now, verify by phoning the Croatan Ranger District in this link
The KOA in Wilmington
is on Market St, about 20 min from the battleship. We've never stayed there.
Carolina Beach State Park
has a campground also, no electric but it is on the island so it gets some ocean breezes, may be good depending on when you go.
As you go south you get to Myrtle Beach, lots of good places there, we've been to Ocean Lakes
for the 10th Anniversary iRV2 Reunion Rally, it's huge with about 1000 sites, well run, resort-like. Of course the sites are closely spaced but you normally go to MB for the things to do, not the beautiful sites.