This sharp looking pin comes from the late 1800s and was used to show support for the Chicago-based Switchmen's Mutual Aid Association, one of America's first railworker's unions. They were makers of fine overalls and work clothes. Only around for about 17 years, they helped form the Swtichmen's Union of North America, which is still around today in some form of names and mergers. Found at Hickoree's Hard Goods.