This Socialist Labor Party button is 1.25" with backpaper by St. Louis Button Co. Text reads "Daniel De Leon/For Congress/S.L.P./9th Cong. Dist." De Leon was the leading figure of the S.L.P. and was at the forefront of the concept of revolutionary industrial unionism. He was among the founders of the Industrial Workers of the World but he soon broke with the organization. In this 1908 New York City race he came in fifth among six candidates. Button Exc. and displays Mint. Rare.