A little more source material those who may be interested;
"If you go through the streets you will see the Japanese mixing with the Chinese, the Hawaiian children playing with the “black Portuguese,” who are called thus because they are descended from the Negroes who were imported long ago from the Portuguese Islands of the African coast in order to labour on the sugar plantations."
New Jersey AAH Curriculum Guide - Unit 2
"The Portuguese are acknowledged by historians to have inaugurated the trans-Atlantic slave trade. In 1441 two Portuguese explorers, Nino Tristao and Antonio Goncalves, sailed to what is today Mauritania in West Africa, kidnapped twelve natives, and returned home to present them as gifts to Prince Henry the Navigator, By 1460, seven hundred to eight hundred African slaves were being taken annually into Portugal, for use mainly as domestic servants. Between 1460 and 1500 the removal of Africans increased as the Portuguese and Spanish established forts and trading stations along the West African coastline. By 1500 about fifty thousand slaves had been taken out of Africa, most brought into Europe, where they were used mainly as domestic servants and artisans and in farming. The remainder were used in the Azores, Madeira, Canary, and Cape Verde islands on sugar plantations in a system that served as a model for the cultivation of commercial crops later in the Americas."
Allen L. Lee