The island was uninhabited and used primarily as hunting grounds until the 1930s, when US 21 was constructed to connect Saint Helena Island with Hunting Island. Development on Harbor Island remained scarce until The Fripp Company, developers of Fripp Island, purchased most of the land on the island and developed a gated residential and resort community. Small-scale commercial development exists along US 21.
Founding dates: Wikidata, Wikipedia, the U.S. post office records of Blevins & Helbock (CC0) and the Census. Homes by year built: Census ACS 2020–24. National Register of Historic Places: National Park Service (list of May 22, 2026). Old photos, postcards and papers: Wikimedia Commons, the Library of Congress and other public archives, credited on each item’s page. Maps: U.S. Geological Survey historical topographic maps (via Esri) and Sanborn fire-insurance maps (Library of Congress). History text and census tables: Wikipedia (CC BY-SA 4.0). Places that used to be: USGS Geographic Names Information System (2021). How TownRatings grades history →
From Wikipedia and the USGS Geographic Names Information System. Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.