U.S. Postal codes

[Barrythevic]

Originally Posted by Big Vito

but was it officially and fully changed over yet?

From the USPS site:

Significant Dates

A quick glance at events.

1775 - Benjamin Franklin appointed first Postmaster General by the Continental Congress
1847 - U.S. postage stamps issued
1855 - Prepayment of postage required
1860 - Pony Express began
1863 - Free city delivery began
1873 - U.S. postal cards issued
1874 - General Postal Union (now Universal Postal Union) established
1893 - First commemorative stamps issued
1896 - Rural free delivery began
1913 - Parcel Post® began
1918 - Scheduled airmail service began
1950 - Residential deliveries reduced to one a day
1957 - Citizens' Stamp Advisory Committee established
1963 - ZIP Code inaugurated
1970 - Express Mail® began experimentally
1971 - United States Postal Service® began operations
1971 - Labor contract negotiated through collective bargaining, a federal government "first"
1974 - Self-adhesive stamps tested
1982 - Last year Postal Service™ accepted public service subsidy
1983 - ZIP+4® Code began
1992 - Self-adhesive stamps introduced nationwide
1993 - National Postal Museum opened
1994 - Postal Service launched public Internet site
1998 - U.S. semipostal stamp issued
2006 - Postal Accountability and Enhancement Act signed
2007 - “Forever” stamp issued
2008 - Competitive pricing for expedited mail began

Want More Postal History?
See our 84-page illustrated booklet The United States Postal Service: An American History, 1775-2006. (PDF) (HTML)