The development of slave narratives from autobiographical accounts to modern fictional works led to the establishment of slave narratives as a literary genre. This large rubric of this so-called "captivity literature" includes more generally "any account of the life, or a major portion of the life, of a fugitive or former slave, either written or orally related by the slave himself or herself". Whereas the first narratives told the stories of fugitive or freed slaves in a time of racial prejudice, they further developed into retrospective fictional novels and extended their influence until common days. Not only maintaining the memory and capturing the historical truth transmitted in these accounts, but slave narratives were primarily the tool for fugitive or former slaves to state their independence in the 19th century, and carry on and conserve authentic and true historical facts from a first-person perspective. They go further than just autobiographies, and are moreover "a source for reconstructing historical experience". The freed slaves that wrote the narratives are considered as historians, since "memory and history come together". These accounts link elements of the slave's personal life and destiny with key historical phenomena, such as the American Civil War and the Underground Railroad.