 Planters and others also purchased slaves in Cartagena, Colombia or Veracruz, Mexico, at trade fairs, and they returned to Peru with the new slaves imported by the slave ships.As a result of the "New laws" of 1548 and the influence of the denunciation of the abuses against Native Americans by Friar Bartolomé de las Casas, slaves gradually replaced natives at the encomiendas.Slave owners in Peru developed preferences to have slaves from specific areas of Africa (believed to have certain characteristics); they wanted to have slaves of one area who could communicate with each other.