 In Mexico, one of Flint's competitors in the rubber industry was Evaristo Madero, the grandfather of future Mexican president Francisco I. Madero.The Maderos had dealings with Flint in the very beginning of the Mexican Revolution, which rightfully prompted historians to suspect Flint's financing of the upheaval.Flint also held large interests in Pierce's endeavors helping the oil magnate stay clear of hated rival John D. Rockefeller who owned the Standard Oil Company.