7/8" litho reads "National Negro Congress Philadelphia October 15-16-17, 1937." Pictures John Brown, the abolitionist and Richard Allen, born into slavery in Philadelphia but emancipated in the Revolutionary era and becoming writer, educator and founder in 1816 of the Africa Methodist Episcopal Church. Reverse has pin-back plus tin insert holds small blue and yellow ribbon accent symbolizing the City of Philadelphia colors. Rare and an outstanding NM example. We've seen only three. See next item.