The American states Ohio, North Carolina, Delaware and California all bear which location name?

While Wilmington California (CA) is only a neighborhood of Los Angeles but the official name of the city's freight harbor area, its namesakes in the other 3 states are fully incorporated cities. Incidentally Harbor City borders Wilmington to the northwest.

There is no known officially stated reason for the name of the Ohio city, but it is close to Cincinnati, whose NFL Bengals used Wilmington College for training camp during their first quarter century-plus (1968-1996).

Both locations in Delaware (DE, 1738) & North Carolina (1739 or 1740) were named in honor of Spencer Compton, Earl of Wilmington, Prime Minister to King George II of England. The area that became Wilmington DE was the first Swedish settlement (1638) in North America, then Dutch (1655), before eventually becoming English.

Wilmington is roughly dead center in the heart of the DE-Maryland (MD)-New Jersey (NJ)-Pennsylvania quad state region. Only DE as a small wedge separates MD (eastern shore) from southern NJ.

The entrepreneur & financier Phineas Banning (1830-1885) treked from his native Wilmington DE to CA, where he acquired land to build the Los Angeles harbor & a nearby ranch estate he named for his birth city. The uploaded photo is the Banning House in Wilmington CA. Besides the freighting business Banning operated a stagecoach line between Wilmington & nearby San Pedro, then later another between Banning (named in his honor near Palm Springs) & Yuma, Arizona.