Captain Sam Buchanan commands a very special tugboat. The 45-foot long “J.W. Westcott II” is also the only floating post office in the United States, and that post office has been operating in one form or another for over 140 years.

Buchanan, who is based in Detroit, cruises up and down the Detroit River delivering mail and packages to ships. The “J.W. Westcott,” which was built in 1949, is the main mailboat, and the “Joseph J. Hogan” serves as a back-up. The mailboats are the only boats in the US to have their own ZIP code: 48222.

The mailboat uses a “mail in a pail” method of delivering mail: It comes alongside a client, and the sailors onboard drop a rope over the side into the tugboat. Buchanan and his crew attach the rope to the delivery that is then hauled aboard the client ship. In addition to letters, Buchanan has delivered cigarettes, coffee, television sets and tooth paste. About ten years ago, he added pizza to the list. On one occasion, he delivered a goat that was being taken to a petting zoo.

In 1874, John Ward Westcott founded what would become the J.W. Westcott Company in a very humble fashion. He used his rowboat to deliver messages to ships traveling to and from Lake Huron and Lake Erie. He also provided “ship to shore” communications in which he passed along messages from various companies instructing their ships where to dock.

Over time, Westcott began delivering mail as well as messages. By the 1950s, the company delivered about a million pieces of mail every season. Since then, due to changes in both communication technology and the shipping industry, that number has been cut in half.