History Lesson:
I grew up in a small town (Armonk, NY) in the era of three-digit phone numbers. Our number was 600, and all you could dial were the other three-digit numbers in Armonk. For any call outside Armonk, you had to go through a long-distance operator. When I was in 6th grade, everyone in Armonk got a 3 added to their number... so ours was 3600. But we still had to dial an operator to place a call outside of Armonk.
Seven digits arrived when I was in high school, and our number became AR3-3600. Suddenly, you could call neighboring towns ... without first dialing an operator. But to call any further (like 10 miles) you still needed to dial an operator to place a "long-distance call."
Area codes (and touch-tone phones) arrived when I was in college. It was like magic. Suddenly you could call any place in the USA without going through an operator. I have occasionally wondered what happened to all the operators who must have lost their jobs through all these "upgrades."
Ten-digit dialing came to Southport, CT (where I now live) about five years ago. It still seems strange to have to dial 10-digits to reach the person next door ... or 11 digits to reach someone two towns away. (Actually, the hardest part is trying to figure out when you have to add "1" and dial 11 digits because it is not always apparent from the number).