The few American cities that introduced this system in the Progressive era, between 1910 and 1930, soon abandoned it - or were forced to - in order to stop the election of black representatives.
Las escasas ciudades estadounidenses que lo adoptaron durante la era progresista, entre 1910 y 1930, pronto lo abandonaron -o se vieron obligadas a hacerlo-para detener la elección de representantes negros.