Note well: Washington is a state, and Washington DC is only a city but the capital of USA. The District of Columbia is a part of the United States, but is not considered a true state, although it is the capital of the United States. Of the 50 states that make up the United Stated of America, Delaware is the oldest; it entered into the Union on December 7, 1787. Delaware was followed 5 days later by Pennsylvania. Hawaii is the youngest of the states; it entered into the Union on August 21, 1959. ZIP Codes are a system of postal codes used by the United States Postal Service (USPS) since 1963. The term ZIP, an acronym for Zone Improvement Plan, was chosen to suggest that the mail travels more efficiently, and therefore more quickly (zipping along), when senders use the code in the postal address.
50 states in alphabetical order :
Alabama, Arizona, Alaska, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin and Wyoming.