Although it might seem like we’ve always used ZIP codes to send snail mail, it was not always so. In fact, it’s only the 50th birthday of the string of digits introduced by the United States Postal Service e to make the mail system a whole lot speedier. So unpopular was the ZIP code at first that the USPS had to embark on a marketing campaign featuring Mr. Zip to convince people to use it. Side note: 99950 is the highest ZIP code in the U.S., for Ketchikan, Alaska. [Time] [More]
