This commemorative envelope was
issued to celebrate the first mail run of the 1980 season for the Detroit River
Mail Boat Service. This unique postal operation is famous for being the only
floating ZIP code (48222) in the United States, utilizing the tugboat J.W.
Westcott II to deliver mail to massive freighters while they are still in
motion. The envelope features a "cachet" (the artwork on the left)
provided by the Motor City Stamp & Cover Club, which depicts the small mail
boat alongside a towering freighter to illustrate the "mail-in-the-pail"
delivery method.
The postmark is dated April 9,
1980, marking the official start of that year's delivery season after the
winter ice had cleared from the Great Lakes. To make it a true collector's
item, it includes both a standard circular date stamp and a special pictorial
cancellation—the ink illustration over the 15-cent flag stamp—which features a
ship and the text "Since 1855." These specific markings verify that
the envelope was actually processed through the Detroit Marine Post Office on
that historic day rather than just being a souvenir print.
