A US address is three lines — recipient, delivery line, then city, state and ZIP — and the apparent simplicity is why so many forms get it wrong. The actual standard is USPS Publication 28, which canonicalises everything the three lines contain: street suffixes (ST, AVE, BLVD), directionals (N, SW), and the secondary-unit designators where most validators overreach — APT and STE require a number, while designators like BSMT and FRNT must stand alone. The two-letter state codes are also a postal invention, defined in the same document, which is why OH is an abbreviation a tax form and a mailing label can agree on.
The ZIP code is the load-bearing element, and it is structured: five digits where the first three identify a sorting facility, plus an optional +4 that narrows to a block face or a single building. The prefix-to-state relationship is strong but not absolute — exactly five of the 911 prefixes in the 50 states and DC serve more than one state, and one more (340, inside Florida's range) belongs to military mail. The full computed numbers, from 00501 at the bottom to 99950 at the top, are collected in our US ZIP code statistics; the per-state detail lives on the state pages.
The city line is where imported data quietly rots. A ZIP does not determine one city name: the Postal Service files parts of Boston under Allston and Dorchester, parts of New York under neighbourhood names, and it accepts either form as correct. The reverse is worse — a city name does not determine a state, since Franklin exists in 27 jurisdictions and Washington in 26, none of them Washington state. The only stable key is the pair: resolve on city plus state, or better, on the ZIP itself.
What this page generates is a format-valid composite: a real city, its real state and a ZIP that genuinely belongs to them, drawn from one postal record, with the street name and house number invented. Above it sits a random American name — a first name and surname from the same US pools the fake name generator draws on — so the record reads as one person rather than a name bolted onto an address. That is what address-form validation, checkout testing and demo data need, and it is all it is. The street is not checked against a delivery-point database and may coincide with a real address. A generated record does not establish residency or authorization to ship there; see the acceptable-use terms.