A minority population of African American residents inhabit the county.
Portuguese forces killed tens of thousands of African residents in retaliation and the war continued for 14 years.
African American residents composed about 30% of the District's total population between 1800 and 1940.
The event is largely attended by current and former African American residents of the city.
African residents made up 0.2%, compared with the city average of 0.3%.
In the 1950s and 1960s, the proportion of African American residents increased.
The cemetery was opened in 1860 as a burial ground for nearby African American residents.
Settlers wanted labour and encouraged existing African residents to stay on the undeveloped land.
Today, the city is believed to have some twenty thousand African residents.