The fort's earthworks were strengthened in 1640 by Governor Peter Hollander Ridder to help defend against the possibility of Dutch or Native American attacks.

The fort's surrender after ten days ended the official Swedish colonial presence in North America, though most of the colonists remained and were allowed to continue their linguistic and religious practices by the Dutch.

In 1938, to celebrate the 300th anniversary of the Swedish colonization of the area, the state of Delaware created a park which contained the Rocks and the site of the former forts.

The Prince presented a gift from their homeland: a monument, topped by a replica of the Kalmar Nyckel, designed by Swedish sculptor Carl Milles.

It is with pride we recall the memory of those almost legendary pioneers who braved the Atlantic in their little vessel, the Kalmar Nyckel, and who came to found the colony of New Sweden.

Their deeds have been considered important enough for the President and Congress of the United States to extend an official invitation to Sweden to take part in the commemorative celebration of this historic event.

In our common acclaim of a historic event of 300 years ago, we stand united, as in our admiration of those early settlers from Sweden who were such worthy and resourceful people.

We are proud to think that their virtue and valor were brought down to their descendants and thus helped in the formation of those traits which we admire in the American people of the present day.

[8] American author and essayist Washington Irving (1783–1859) refers to Fort Christina in the opening pages of his short story "Rip van Winkle", describing the genealogy of his Dutch protagonist: In that same village, and in one of these very houses, (which, to tell the precise truth, was sadly time-worn and weather-beaten), there lived many years since, while the country was yet a province of Great Britain, a simple good-natured fellow named Rip Van Winkle.

He was a descendant of the Van Winkles who figured so gallantly in the chivalrous days of Peter Stuyvesant and accompanied him to the siege of Fort Christina.