1) an expedited delivery service provided to the general public by the <#usps=Postal Service> since 1971. 2) a premium priced government service in the early (pre-stamp) 19th century. 3) a private service provided since the mid-19th century by companies such as <#wellsfargo-gen=Wells, Fargo and Co.> which operated "The <#ponyexp=Pony Express>." An 1845 law prohibited private express companies from carrying letter mail unless regular <#postage> was paid in addition to the express company charges.