Introduction of the ZIP Code
Introduction of the ZIP Code came on July 1, 1963, when the U.S. Post Office Department launched five-digit Zone Improvement Plan codes to speed mail sorting as volume outgrew the city postal zones used since 1943.
What happened and why it matters
ZIP Codes are the hidden backbone of U.S. parcel shipping, because carriers use them to sort packages, define delivery areas and calculate shipping zones. Mail volume had doubled between 1943 and 1962, and the new codes let clerks route mail by number instead of by memorized geography; postal inspector Robert Moon is credited with designing the first three digits. Two-letter state abbreviations followed that October, and ZIP+4 followed in 1983. Today the origin and destination ZIP Codes set the zone on USPS, UPS and FedEx rate tables, and ZIP Codes also drive delivery area surcharges and address validation.
Related events
Sources
- ZIP Code (Wikipedia) en.wikipedia.org
- U.S. Post Office introduces ZIP codes (HISTORY.com) history.com
- Zip-a-Dee-Doo-Dah: The ZIP Code is 50 (Library of Congress) blogs.loc.gov