1.25" button has rarely seen backpaper reading "McMahon Bros. Pittsburgh, Pa." The reverse collet holds 3" ribbon. Celluloid has real photo portraits with text "Our Presidents/John P. White/Van Bittner." White was president of the UAW 1911-1917. Van Bittner began as a local president and spent forty years as an organizer and loyalist of John L. Lewis. Text on the ribbon reads "Labor Day Celebration/U.M.W. of A./Smithton, Pa./Sept. 6th, 1915/" (plus a list of three local union names and numbers). Very minor age on the ribbon. The cello is essentially Mint. First we've seen. See rare railroad strike of 1923 button #724.