In the larger populated cities of the time, merchants found a way to cater to busy customers who had little time or energy to prepare food during the evening. The variation in Chinese cuisine from different regions led caterers to create a list or menu for their patrons.
ZIP Code began on July 1, 1963, as scheduled. Use of the new code was not mandatory at first for anyone, but, in 1967, the Post Office required mailers of second- and third-class bulk mail to presort by ZIP Code. Although the public and mailers alike adapted well to its use, it was not enough.
A ZIP Code is a five digit number that identifies a specific geographic mail delivery area. The acronym ZIP refers to Zone Improvement Plan, a plan implemented by the USPS in the early 1960âs to improve the sorting and delivery of mail. There are approximately 43,000 ZIP Codes in the United States.