digging into shipyards that built more than 100 ships:
Sun Shipbuilding and Drydock Co. Chester, Pennsylvania: Race track and condos.
Bethlehem Fairfield, Baltimore, Maryland: RORO Parking lot, plenty of room, still has Rail access.
North Carolina Shipbuilding Wilmington, North Carolina: Has become Port of Wilmington, but still has rail access.
Southeastern Shipbuilding, Savannah, Georgia: In the process of being gentrified, but there is still land there and still rail access.
J.A. Jones Construction, Brunswick, Georgia: Open park, still has rail access, ramps still there. (technically only built 99 but close enough)
Seattle-Tacoma Shipbuilding: Tacoma, Washington: Seattle, is now container terminal. Tacoma still has rail, still has land.
Kaiser Richmond: Still has Rail, graving docks, RORO parking lot.
Oregon Shipbuilding, Portland: Coordinates on WIkipedia shows it’s currently a scrap terminal, but about a mile south is a giant fucking roro parking lot, with rail connection.
California Shipbuilding, Terminal Island, Los Angeles, California: Container terminal now.
Kaiser Vancouver Shipyard, Vancouver, Washington: Looks like the original buildings are there, ruins of the slipways are there, still has rail.
I hit enter too fast but my Moring google maps exercise and this Wikipedia article leads me to believe that with some immanent domain and another emergency shipbuilding act, it will be easier than the first time.