Incidents in the Life of a Slave Girl is a particular type of memoir called an enslaved person's narrative. Like other enslaved people's narratives, such as Frederick Douglass's, the memoir documents the events of Jacobs's life during her enslavement and after she escapes. Also like other enslaved people's narratives, it is both a memoir and a persuasive document written for people who might be convinced to join the abolitionist cause.
The memoir is based on fact, but it emphasizes events in Jacobs's life that are tropes in this type of book. For instance, she describes learning to read. Reading was an extremely valuable skill for enslaved people trying to escape. Literacy rates among everyone in the pre-Civil War South were low because enslavers (who essentially controlled the economy and politics) knew that reading led to radicalization and organizing against the institution of slavery. Literacy allowed people to read the Bible for themselves. As readers see in the book, this ability allows Linda to question how Christianity is used to justify enslaving Black people.
Reading also appears in many enslaved people's narratives as a deliberate signal of Black people's humanity and intelligence. Jacobs and other writers of enslaved people's narratives knew that even sympathetic white readers were steeped in racist propaganda falsely claiming that Black people were inferior and, in some cases, more akin to animals than humans. Getting white people to actually fight against the institution of slavery would require combating the effects of this propaganda, convincing them that Black people were just as deserving of human rights as white people. White readers who may have bought into racist stereotypes about Black people could connect with the "characters" in enslaved people's narratives over their discovery that they love to read. They could then point to depictions of literate Black people as evidence against the false idea that enslaved Black people would not be able to handle themselves as full citizens of the United States.
Like many enslaved people's narratives, the book also uses some of the conventions of sentimental novels. Jacobs fictionalizes herself as Linda Brent to protect herself from those who might still try to bring charges against her from running away from the Flints. But this fictionalization also allows her to fashion the events of her life after the plot of a novel. By the mid-19th century, novels were extremely popular. Sentimental novels were especially popular during this period. In these novels, readers often followed the ups and downs of a young woman's life as she attempted to avoid having extramarital sex (or, in many cases, as she attempted to avoid being sexually assaulted before marriage). Samuel Richardson's Clarissa, for instance, is an extremely long novel about a young woman trying to protect her virtue from a man who aggressively pursues her. Jacobs draws on white readers' familiarity with novels like Clarissa to help them understand her defiance of Dr. Flint not as attempt to cheat him, but rather as an attempt to protect herself from his sexual advances. Because white readers had a track record of getting invested in the outcomes of sentimental novels, these novels' tropes were an effective way for many enslaved people's narratives to get widespread attention and buy-in.