One of the earliest examples of postal worker camaraderie after hours is the creation of letter carriers’ bands through the National Association of Letter Carriers (NALC). The NALC was organized in 1889 and letter carriers’ bands arrived soon after.
There are conflicting accounts about which band existed first, but Chicago, Cleveland, Minneapolis, St. Louis, Milwaukee, Omaha, New York, New Jersey, Philadelphia, Jersey City, and Newark letter carriers’ bands were all in existence by 1900.
(Info Courtesy: Smithsonian - National Postal Museum)