Several of the rivers hold protected status for their salt marsh wetlands bordering the bay, which serves as a breeding ground for many aquatic species, including horseshoe crabs.

Many birds like red knots use this Bay area to fuel up their energy reserves on horseshoe crab eggs after the long journey.

[10][11] As part of the New Netherland colony, the Dutch established several settlements (the most famous being Zwaanendael) on the shores of the bay and explored its coast extensively.

The thin nature of the corporate colony's presence in the bay and along what was called the South River (now the Delaware) made it possible for Peter Minuit, the former director of New Netherland, to establish a competing Swedish sponsored settlement, New Sweden in 1638.

Conflicting crown grants were made to the James, Duke of York and William Penn on the west bank of the bay and river.

Settlement grew rapidly, leading Philadelphia, upriver on the Delaware, to become the largest city in North America in the 18th century.

Penn viewed access to Delaware Bay as being so critical to Pennsylvania's survival that he engaged in an eighty-year long legal boundary dispute with the Calvert family to secure it.

During the French and Indian War the dissemination of Joshua Fisher's original publication of the "Chart of Delaware Bay" was restricted by the authorities as its accuracy might advantage an enemy approach.

[12] In 1782 during the American Revolutionary War, Continental Navy Lieutenant Joshua Barney fought with a British squadron within the bay.