What point was equiano trying to make by including details about life in africa

Equiano was a freed slave that wrote an autobiography that contributed to the change of heart of many people regarding slavery and that ultimately contributed to the end of slavery. 

His autobiography included his life before being kidnapped in Africa, and I think that he was trying to stress that he had a normal life before and that being taken away from this life (due to the institution of slavery) was wrong and immoral - that supported the idea that slavery should be abolished