Darien's earliest roots trace back to around 1641, when colonists from Wethersfield first settled the area as part of Stamford. The community grew slowly around three original settlements: Noroton Cove, Gorham's Landing, and the head of the Five Mile River, before finally gaining its own religious identity as Middlesex Parish in 1737.

For decades, Middlesex Parish residents petitioned for independence from Stamford, seeking local control over their own taxation, schools, and church affairs. That independence finally came on May 13, 1820, when the Connecticut General Assembly incorporated the Town of Darien, named for the Isthmus of Darien in present-day Panama, a nod to the maritime trade that shaped the town's early economy.

The arrival of the New York and New Haven Railroad in 1848 shifted the center of town life from the old harbor at Gorham's Mill to a new commercial hub around the railroad station on the Post Road, a shift that still defines Darien's downtown today. As the railroad made commuting to New York possible, wealthy families increasingly chose Darien as a home, either for the summer or year round, cementing its place on Connecticut's Gold Coast.