Herbert Spencer
Spencer's term does strongly suggest natural selection, yet as he extended evolution into realms of sociology and ethics, Spencer made use of Lamarckism rather than natural selection, so it seems he was not a Darwinian after all. Others took up his social ideas, and drew the conclusion that it was useless to try and help the poor, and that competition without limits was the way society should go. Darwin himself did not accept these ideas, but they were quite widespread in the United States at the end of the nineteenth century.