The irony of literacy
Unfortunately, this memoir is the only surviving one of its kind from this portion of history, because Black people were not often literate in 1850 America, since it was illegal to teach them to read in most of the country. His literacy allows him to read and learn, and it allows him to flourish in ways that he might not otherwise be allowed to. It is ironic, because his literacy is his only real compensation for his difficult life, and because his memoirs have been historically important, though they are about his feeling unimportant and disenfranchised.
The irony of innocence and guilt
The reader must decide whether they trust Austin Reed about his claims to innocence. In any case, he observes a tragic irony that is historically accurate. As an African American, he is ironically disenfranchised from justice because racist opinion keeps people from considering that he might be innocent. Sometimes he admits to crimes, but sometimes he says he is innocent, leaving the reader to judge him or not.
The ironic job on the farm
Although he is not technically a slave, while he works for the farmer he can't help but notice how similar his life is to slavery. He works for meager pay doing long days of hard work in the sun. He ends up apprenticing for the farmer, but in a twist of fate, he is ironically removed from the farm by an accusation of arson that sends him back to jail.
The irony of historicity
Although Reed claims he did not start the fire on the farmer's land, historical evidence suggests that he might have been guilty. This means that ironically, he might be lying about more things than this, or perhaps he is truly innocent. The historicity of his claims adds a layer of confusion and meta-narrative to the text, because the reader must try to empathize with him, knowing that he is an imperfect person under extreme duress.
The irony of escape
Not only is he unable to escape his final imprisonment, he is also unable to escape his vices of gambling and theft. He admits that he is sometimes unable to help himself, which adds irony to his point of view, because he might have valid points of criticism, but he is unable to fix himself, suggesting that he is both a victim of disenfranchisement, and in other ways, perhaps he is not a victim. The questions are complicated. He hopes to escape to a better life, but all he finds is imprisonment and disenfranchisement.