As a political document, such a detailed, visceral description of life on board the slave ship in Vassa's autobiography was very useful in eliciting sympathy, and Vassa was well aware of this.  
He crossed the Atlantic to Barbados and then to Virginia, where he was renamed Jacob. After a few days in Virginia, he was bought by Michael Henry Pascal, a British naval captain, for $£ 40$. Captain Pascal took him to England around early 1755. His new master renamed him Gustavus Vassa, the name he would come to bear for the rest of his life. It is worth noting, as Lovejoy has argued, that Vassa recounts in his autobiography that he initially rejected the name given to him by Pascal, that he in fact refused to answer to the name because he was unwilling to let go of the name Jacob. Lovejoy speculates, convincingly, that Vassa's protestation could only have been in hindsight, as Vassa could only have understood the significance of the Biblical name Jacob years later, and could also only have understood the significance of being named after Gustav Vasa, the King of Sweden, who was, at the time, a national hero (Lovejoy, 2012, pp. 164-184). Lovejoy notes:  
The idea that he was literally beaten into acceptance of this name is worth pausing over [...] It was an immodest way by which he informed his readers that he had only reluctantly accepted his fate [...] Vassa was obviously giving himself agency, even if his resistance was suppressed, but surely he projected his later knowledge of his namesake as an implicit recognition of his own authority. Vassa appears to have attached significance to his assigned name because it drew on public knowledge of the Swedish monarchy, although in 1755 at the time he was allegedly protesting, he could not possibly have known this, any more than he would have known that Jacob climbed a ladder and confronted God (Lovejoy, p. 168).