In what year and for what purpose were the * and # signs added to telephone dialing devices?

Question

The rotary phones of my youth only had 1-9 and 0 for dialing. I remember push-button telephones coming about, and the options of pulse or touch-tone... but until advanced call services were offered, what were the * and # for? Were they included with the first push-button phones or added later?

Answer 1

They were added as soon as touch tone dialing was offered. They were used for signaling as part of business phone systems (getting supervisory circuits and setting-up unique call combinations).

As soon as the documentation on them was published Phone Phreaks had blue boxes that they used to get free calls with those buttons.

Answer 2

Actually the * and # were not originally introduced at the same time as touch tone dialling.  Touch tone was introduced in 1963/64 and the phone had a 10 button dial pad (no * or #).  The phone was a model 1500.  In 1967 the 2500 model was introduced with a 12 button dial pad  (contained a * and #).

See information and pictures here:

http://www.porticus.org/bell/telephones-...