Who is Harriet Jacobs in Incidents in the Life of a Slave Girl?
The short answer to your question is that Harriet Jacobs is the author of Incidents in the Life of a Slave Girl. This story is noteworthy because it is the first significant, published slave narrative told from a woman's perspective.
Harriet Jacobs was born in North Carolina in (or near) 1913. Unlike most slaves, Jacobs was taught to write when she moved, at the age of six, to a new mistress's home. Despite some advantages like this, her life was full of the heartbreaking drama which so many slave women endured. Jacobs was careful to use fictitious names to protect her family (which is why, for many years, there was some question about whether the story was a true or fictional account).
She was hesitant to write her story, naturally, because she was unsure of her ability to write effectively. In the preface to the narrative she writes:
I do earnestly desire to arouse the women of the North to a realizing sense of the condition of two millions of women at the South, still in bondage, suffering what I suffered, and most of them far worse.
With this as her motivation, she wrote and published this autobiographical narrative, considered to be just as significant as other slave narratives, such as Frederick Douglas's.