“Some time back”? You might say! Non-mandatory five-digit ZIP Codes were introduced nationwide on July 1, 1963 — only 55 years ago.
“Non-mandatory five-digit ZIP Codes were introduced nationwide on July 1, 1963”
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I’m thinking more of when the two-letter state abbreviations became pretty much standard. That coulda been 1963, but I think it was later on. I’m too lazy too google it up, lol.
But now that I think on it, the 50s Chuck Berry song “Sweet Little Sixteen” used the 2 letter abbreviation for Penn - “They’re really rockin’ in Boston and Philadelphia PA”.