What style of writing did Frederick Douglass use in his autobiography?

It is
important, too, to acknowledge the structure of the narrative.

It begins with
a preface, written by William Lloyd Garrison, a well-known Massachusetts abolitionist, publisher
of The Liberator, an anti-slavery newspaper, and a friend and associate of
Douglass. In this preface, Garrison certifies that "Mr. Douglass has very properly chosen
to write his own Narrative, in his own style, and according to the best of his ability, rather
than to employ someone else." Thus, the reader has the certification of a white man that
Douglass is, indeed, eloquent enough to tell his own story and that his story is the truth.

This preface is followed by a letter to Douglass from Wendell Phillips,
Esq., another leading abolitionist of the time. While Garrison's words validate Douglass's
ability to tell his own story, Phillips's letter validates Douglass's ability to narrate
history. His voice, Phillips asserts, would be instrumental in wrenching narrative authority
from the masters.

In telling his own...