Comparison

Olaudah Equiano wrote a narrative from the perspective of a slave to release the cruelties of the international slave trade.
John wrote his narrative as an informative persuasive essay. He used his novel to lure people over from Britain to settle in the new land and to make himself appear to be a local superhero. 
William Bradford wrote his novel as an inform people not only across the sea but also as a historical document. Bradford's novel is the most trustworthy out of the three because he does not try to benefit from his work. In fact he doesn't even include himself in the novel. He simply recites what happens to the Pilgrims as a whole.