The first 5-digit zip code ever administered in America is 00601 for the town of Adjuntas, Puerto Rico. Shortly after, Agawam, Massachusetts received the zip code 01001.
Agawam became the second town in the U.S. to have a 5-digit zip. This also made it the first town in the continental United States to have a zip code.
Brief history of the zip code
Inspiration for the U.S. zip code stemmed from 1850s London, the birthplace of the world’s first postal code system. Sir Rowland Hill divvied up the city into 10 unique postal districts to make mail delivery easier.
In the 1920s, the U.S. started to face its own challenges with mail delivery and zip codes became an important subject of discussion.
In 1943 mail volume doubled in the U.S. and zip codes were institutionalized to help postal carriers. 1943 was the birth of the 1-2 digit zip code which looked very different than the ones we use today.
5-digit zip codes in the U.S.
While helpful, the lack of a standardized system for zip codes created a necessity for change. In 1963, Adjuntas, Puerto Rico received its 5 digits. That was the beginning of the 5-digit zip code system we use today in the U.S.
Agawam, Massachusetts was the next place to receive a 5-digit zip. This made it the first town in the continental United States to receive a 5-digit zip code.
Massachusetts also received its preliminary zip numbers 010-027. The first 2-3 numbers of the zip code signified the state the mail was going to, so it was easier to sort.
About Agawam, Massachusetts
The Hampden County town of Agawam was settled in 1636 and incorporated as town in 1855 and as a city in 1973. It sits in southwestern Mass., right along the Connecticut border. The population at the time of reciving its zip code in 1963 was about 16,000. Today, the population is nearly 29,000.
Agawam is also home to Six Flags New England, the 235-acre theme park.