In the United States and Canada, area codes were first allocated in 1947 and some large cities used soon after as operator routing codes for connecting long-distance telephone calls between toll switching centers.
Area codes were first allocated in 1947. This was in the United States and Canada. Area codes were first allocated in some large cities used soon after as operator-distance telephone calls between toll switching centers. This was in the United States and Canada. This operator was routing codes for. This operator was connecting long.