All-Number Calling

All Number Calling (ANC) is a telephone numbering system that was introduced in the United States in the 1960s to replace the traditional system of using telephone exchange names as the first part of a telephone number.

Until the 1950s, local telephone numbers consisted of an exchange name and a 4 or 5-digit subscriber number. The first two or three letters of the exchange name translated into digits given by a mapping typically displayed on the telephone's rotary dial. For example, a New Yorker's phone number might have been CHelsea 4-5034, which another user would dial as the digit sequence 2445034, translating C into 2, and H into 4.

After World War II, and particularly in the 1950s and 1960s, demand for telephone service strained not only the resources of the telephone operators, but also the network system of telephone exchanges and the traditional numbering plan using telephone exchange names. It was necessary to begin using digit combinations that could not be expressed by memorable names.

All-Number-Calling was introduced quietly first in small communities where it was met with little resistance. In other areas this change sparked an intense outcry among urban users and, who considered all-digit dialing to be dehumanizing.

Opponents created a variety of organizations to oppose all-number calling, including the Anti-Digit Dialing League and the Committee of Ten Million to Oppose All-Number Calling to pressure AT&T to drop the plan.