The Delaware City Historic District, Chelsea, Eastern Lock of the Chesapeake and Delaware Canal, Fairview, and Fort Delaware on Pea Patch Island are listed on the National Register of Historic Places.
•
The Diamond State Base Ball Club is a non-profit amateur organization created for the purposes of providing physical fitness to its members, educating the public on the history of baseball and local history, and serving as a point of public pride.
New York City | Mexico City | Kansas City, Missouri | Kansas City | Salt Lake City | Quebec City | Oklahoma City | City of London | Delaware | city | Vatican City | New York City Subway | Panama City | Kansas City Chiefs | Wilmington, Delaware | Kansas City Royals | Sex and the City | Mayor of New York City | Delaware River | Atlantic City, New Jersey | Utrecht (city) | Cork (city) | New York City Ballet | Manchester City F.C. | Jersey City, New Jersey | New York City Opera | Guatemala City | Atlantic City | Quezon City | City College of New York |
On May 20–21, 2010, the Diamond State Base Ball Club, in cooperation with the Governor Walter W. Bacon Health Center, Fort DuPont State Park, the Town of Delaware City and the Mid Atlantic Vintage Base Ball League, hosted the First State 19th Century Base Ball Festival at the Fort DuPont Parade Grounds.
That subsidiary has, in turn, created four wholly owned chemical manufacturing subsidiaries in Delaware City, Delaware, Illiopolis, Illinois, Baton Rouge, Louisiana, and Point Comfort, Texas.
Fort du Pont at Delaware City and Fort Miles at Cape Henlopen became major military installations protecting the shipping routes into the Delaware River.