Black text on a white background with red outlined text above and an illustration of stars on a blueish purple background
Founded in 1889, The National Association of Letter Carriers (NALC) is an American labor union, representing letter carriers employed by the United States Postal Service (USPS). The NALC has 2,500 branches in the the United States, District of Columbia, Puerto Rico, Virgin Islands, and Guam. Over 93% of letter carriers are members of the NALC, and the union is recognized as the bargaining agent for all carriers. Membership in the NALC is completely voluntary. This button is most likely referring to the 100th anniversary of the establishment of the NALC which would have occurred in 1989.