1.75” without backpaper used by the “North Dakota” delegation to a convention titled “N.C.B.A., Milwaukee, Oct. 20-24. 1902.” We can’t find an organization name that matches these initials which dates back to as early as 1902 but undoubtedly this was some sort of a dairy farmers organization. Couple of tiny light marks around the rim but still VF. Hake Book Collectible Pin-back Buttons photo example Cattle Section #97. Comes with Hake’s COA. Also see Commission Merchant Button in Spanish American War Section #631.