Explaining on Instagram: "The ZIP code system was introduced in the United States in 1963 under the “Zone Improvement Plan.” It was created to keep up with the nation’s booming population and growing mail volume, which had outpaced older methods of sorting and delivery. Before ZIP codes, postal workers relied on personal knowledge of neighborhoods to route letters and packages, a system that quickly became outdated as cities expanded and suburbs spread. The five-digit ZIP brought order to the ch

Purely History on Instagram: "The introduction of ZIP codes in 1963 marked a turning point in how mail was organized and delivered in the United States. Before then, postal workers relied heavily on local knowledge and often faced confusion with similar street names or growing urban areas. The new system, short for “Zone Improvement Plan,” gave every address a simple five-digit code that streamlined sorting and sped up delivery. What started as a practical fix for an overburdened postal system b