One point that I haven't seen mentioned elsewhere is that as far as I can tell, Equiano was one of the first people to use the phrase "human rights". Wikipedia thinks that "The term human rights probably came into use some time between Paine's The Rights of Man  and William Lloyd Garrison's 1831 writings in The Liberator", but Equiano's Interesting Narrative is published in 1789, the year that the French National Assembly passed its Déclaration des droits de l'homme et du citoyen and two years before Paine. He uses the phrase twice, first with reference to the African slave traders who parted him forever from his sister (they had been captured together):
From the time I left my own nation I always found somebody that understood me till I came to the sea coast. The languages of different nations did not totally differ, nor were they so copious as those of the Europeans, particularly the English. They were therefore easily learned; and, while I was journeying thus through Africa, I acquired two or three different tongues. In this manner I had been travelling for a considerable time, when one evening, to my great surprise, whom should I see brought to the house where I was but my dear sister! As soon as she saw me she gave a loud shriek, and ran into my arms--I was quite overpowered: neither of us could speak; but, for a considerable time, clung to each other in mutual embraces, unable to do any thing but weep. Our meeting affected all who saw us; and indeed I must acknowledge, in honour of those sable destroyers of human rights, that I never met with any ill treatment, or saw any offered to their slaves, except tying them, when necessary, to keep them from running away. When these people knew we were brother and sister they indulged us together; and the man, to whom I supposed we belonged, lay with us, he in the middle, while she and I held one another by the hands across his breast all night; and thus for a while we forgot our misfortunes in the joy of being together: but even this small comfort was soon to have an end; for scarcely had the fatal morning appeared, when she was again torn from me for ever!The second incident is an ugly affair at Montserrat:
While we lay in this place a very cruel thing happened on board of our sloop which filled me with horror; though I found afterwards such practices were frequent. There was a very clever and decent free young mulatto-man who sailed a long time with us: he had a free woman for his wife, by whom he had a child; and she was then living on shore, and all very happy. Our captain and mate, and other people on board, and several elsewhere, even the natives of Bermudas, all knew this young man from a child that he was always free, and no one had ever claimed him as their property: however, as might too often overcomes right in these parts, it happened that a Bermudas captain, whose vessel lay there for a few days in the road, came on board of us, and seeing the mulattoman, whose name was Joseph Clipson, he told him he was not free, and that he had orders from his master to bring him to Bermudas. The poor man could not believe the captain to be in earnest; but he was very soon undeceived, his men laying violent hands on him: and although he shewed a certificate of his being born free in St. Kitt's, and most people on board knew that he served his time to boat-building, and always passed for a free man, yet he was taken forcibly out of our vessel. He then asked to be carried ashore before the secretary or magistrates, and these infernal invaders of human rights promised him he should; but, instead of that, they carried him on board of the other vessel: and the next day, without giving the poor man any hearing on shore, or suffering him even to see his wife or child, he was carried away, and probably doomed never more in this world to see them again. Nor was this the only instance of this kind of barbarity I was a witness to.It's interesting that both of Equiano's usages of the phrase come in descriptions of slavers brutally breaking family ties, rather than in talking of any of the other numerous abuses he witnessed.
Anyway, this is an amazing book whose title rather under-sells it to a modern audience.