Irony of At-mun's Kingship
In his own country, At-mun was the prince of his tribe and village. When his father, the chief, is killed during the slavers' raid, he becomes a king. Ironically, he is forced to take the position of a slave despite his kingship, a position even lower than that of a mere servant. This irony is present throughout Amos's life in America, but it is especially notable when Roxanna, Caleb Copeland's daughter, is teaching him about Christianity and tells him that, after being saved by Christ, he is a king.
Irony of Race Relations
Slavery is generally seen as a terrible atrocity that resulted in harsh bitterness between the black slaves and their white masters (as was really the case in most circumstances). For Amos, though, the experience was very different: he was hardly treated as an inferior, and he enjoyed very good relationships with both of his masters and their families.
Irony of Amos's Second Auction
After Copeland dies, Amos is sold again at another auction. By this time, Amos is a competent English-speaker and even possesses his own money; he even bids on himself, ironically, eliciting laughs from the people in attendance. Despite this virtual freedom, he is again sold to a white man, and he dutifully goes along with him.
Irony of Amos's Wives
Three times in his lifetime, Amos buys the freedom of a female African slave and marries her. For the first two, Lily and Lydia, he saves up his money for a long time and finally frees them only to watch them die within a single year of their liberation. This anticlimax might seem ironic, but Amos is surprisingly content with it; he's happy he allowed them to die in freedom.
Irony of Ath-mun
For most of his life, Amos keeps on the lookout for his sister, Ath-mun, who might be coming in on another slave ship, so he can free her as well. Ironically, he's been looking for the young woman he remembered, forgetting that just as he himself had aged, she has aged as well, and this realization causes him to despair - she might have come through long ago and he wouldn't have noticed.
