The Maganja da Costa District had become the stronghold of the Afro - Portuguese Alves da Silva family after the final banning of the legal slave trade in 1830 .
The Maganja da Costa District contained a number of aringas manned by the family 's chikunda .
The Maganja da Costa District had become the stronghold of the Afro - Portuguese Alves da Silva family after the final banning of the legal slave trade in 1830 , and contained a number of aringas manned by the family 's chikunda .