Harriet Jacobs was an African-American woman living in the nineteenth century. At the time of her birth, slavery still prevailed in the southern United States, and she was born a slave. She later escaped and was forced to live in hiding in various attics, unable to have proper contact with her children. Eventually, she reached the northern United States and was able to work as a nursemaid. By this point in time, laws in New York State, where Jacobs had ended up, meant that all slaves were freed. At this juncture, Jacobs became extremely involved in anti-slavery work, particularly after a journey to England with her employer opened her eyes to the lack of segregation in other countries.
Jacobs wrote her autobiography in 1853 under the psuedonym of Linda Brent. Because Jacobs used a pseudonym, there was much debate over the actual authorship of the manuscript—famous names were suggested as the possible author, such as Harriet Beecher Stowe. Ultimately, it was determined by many that the book must be fictional. Prevailing academic opinion for many years was that the author was Lydia Marie Child. Only in the 1980s was Harriet Jacobs finally recognized as the actual author.
We don't actually know why Jacobs chose to use a psuedonym, but some have suggested that it was because the story was so personal to her, and she wanted to maintain a sense of privacy, rather than generate huge interest in her life and publicize the fact that she was born into slavery. Others have suggested that the publisher may have asked Jacobs to use a psuedonym in order to stimulate interest in the true identity of the author and facilitate the situation which did actually occur, in which readers began to speculate on the identity of the author.