North American NumbersArea code history
Search any North American area code to see how it came to be — or open a metro history pack that traces how one original code split and overlapped into a whole family.
Metro history packs
Deep, source-cited lineage stories for major numbering regions — a genealogy diagram, dated timeline and every affected code linked.
How Los Angeles's Original Area Code Split Into Today's Core Codes
When the first North American Numbering Plan was drawn up in 1947, a single area code — 213 — served a broad Southern California t...
Open the Los Angeles pack →New York City
A source-cited history pack for New York City is being researched and will publish with the same discipline.
San Francisco Bay Area
A source-cited history pack for San Francisco Bay Area is being researched and will publish with the same discipline.
Chicago
A source-cited history pack for Chicago is being researched and will publish with the same discipline.
Toronto
A source-cited history pack for Toronto is being researched and will publish with the same discipline.
Every area code also carries its own dated history on its profile — search above, or browse by state / province. For term definitions see NumberGlossary; for underlying data, NumberResearch.