3617841 Black Panther Convention, Lincoln Memorial, 1970 (b/w photo) by O\'Halloran, Thomas J. (fl.1957); Private Collection; (add.info.: Warren K. Leffler also identified as photographer Black Panther Party (BPP originally Black Panther Party for Self-Defense) was a revolutionary black nationalist and socialist movement who organised the Revolutionary People\'s Constitutional Convention first in Philadelphia then in Washington); American, out of copyright.