A new nationwide numbering plan was officially published in October 1947 in cooperation of the Bell System with the independent telephone operators. The plan divided most of North America into eighty-six numbering plan areas (NPAs). Each NPA was assigned a unique three-digit code, typically called "NPA code" or simply "area code". These codes were first used in Operator Toll Dialing by long-distance operators in establishing calls between toll offices. The first customer-dialed direct call using area codes was made on November 10, 1951, from Englewood, New Jersey, to Alameda, California. Direct distance dialing (DDD) was subsequently introduced across the country. By the early 1960s, most areas of the Bell System had been converted and DDD had become commonplace in cities and most towns in the United States and Canada. By 1967, the number of assigned area codes had grown to 129.