The 411 on 911

How did they come up with 911 as the emergency phone number? The first number is in the lower right section of the keypad and the last two are in the opposite corner. It's been around for many years right, even back when most of the phones were rotaries? You know how long it takes to dial 9 on a rotary? Anyone who remembers back that far, if you had to dial a 9 in your phone number, you would stick your finger in the slot, pull the dial back to that beer tab looking thing and release it. You had so much time while the 9 was dialing you could go put on an Iron Butterfly record, play through the whole thing, come back and put in the rest of your number. And God help you if you had two or more 9's in there. You felt like your index finger was broken by the time you were done.

I was just curious why they gave the people who are most desperate at the time of dialing the hardest 3 digit number to dial (are you sure you don't want to make it 919?) and for the people who want to look up where Uncle Harvey lives the more efficient number. Right there, boom, 4-1-1.