History of 911

Why 9-1-1?
When designing the first emergency response system, the first question that needed to be answered was which numbers to use. Why was 9-1-1 selected?
When the task force convened to consider such a question, some initial parameters were set. It was going to be a three-digit number, and the first digit could not be "1" or "0."
When this system was originally put in place, most people were using rotary dial phones. For expediency, there was no question that the second and third numbers should be "1." So the real debate centered on which first number to use.
Among the most compelling reasons for settling on "9" was that it would be easy to find in the dark. Simply, locate the last hole on the dial, the "0" and back up one. Or for a touch pad, find the bottom right button, the "#" and move up one.
Thus, the emergency 911 code was born.

At this point in 911's history, it was very important that the dispatcher at the PSAP obtain information from the caller about where he or she was and what kind of emergency service was required, then dispatch the correct authorities. As you might imagine, this required some skill in dealing with people under the stress of an emergency. Even then, details about where to send responders could often be hard to get. This breakdown facilitated the development of Enhanced 911.