860 Area Code – Hartford, Connecticut: Location, Time Zone & History

Hartford has been called the "Insurance Capital of the World" since the 19th century, and that concentration of insurers -- The Hartford, Travelers, Aetna -- sits at the center of area code 860. Connecticut had only ever known a single area code, 203, until it was split on August 28, 1995: 203 shrank to the state's southwestern corner while 860 took most of the rest -- Hartford, most of Litchfield, Middlesex, New London, Tolland, and Windham counties. Mandatory 10-digit/860 dialing followed on October 4, 1996.

Growth eventually caught up with the new territory. Statewide 10-digit local dialing became mandatory on November 14, 2009 to prepare the ground, NANPA issued a planning letter in 2013 announcing an all-services overlay, and area code 959 went into service on August 30, 2014 -- Connecticut's second overlay after 203's own 475.

Beyond insurance, the 860/959 territory is home to General Dynamics Electric Boat's submarine works in Groton, the University of Connecticut's main Storrs campus, and two of the country's largest casino resorts, Foxwoods and Mohegan Sun, both in New London County. Mark Twain wrote many of his best-known works at the Mark Twain House in Hartford's Nook Farm neighborhood, and the Cross Sound Ferry links New London across Long Island Sound to the 631 numbering plan area in New York.