The Connecticut panhandle is the southwestern appendage of Connecticut, where it abuts New York State. It is contained entirely in Fairfield County and includes all of Greenwich, Stamford, New Canaan, and Darien, as well as part of Norwalk and containing some of the most expensive residential real estate in the United States.
The irregularity in the boundary is the result of territorial disputes in the late 17th century, culminating with New York giving up its claim to this area, whose residents considered themselves part of Connecticut, in exchange for an equivalent area extending northwards from Ridgefield, Connecticut, to the Massachusetts border as well as undisputed claim to Rye, New York.
The two British colonies (at that time not yet U.S. states) negotiated an agreement on November 28, 1683, establishing the New York–Connecticut border as 20 miles (32 km) east of the Hudson River, north to Massachusetts. The 61,660 acres (249.5 km2) east of the Byram River making up the Connecticut Panhandle were granted to Connecticut, in recognition of the wishes of the residents. In exchange, Rye was granted to New York, along with a 1.81-mile (2.91 km) wide strip of land running north from Ridgefield to Massachusetts alongside Dutchess, Putnam, and Westchester Counties, New York, known as the "Oblong".