Answer: The tone in this excerpt is solemn, witty, outspoken and persuasive.
Explanation: The tone of a literary work can be understood as the approach or the attitude that the writer conveys towards the subject of his or her work. Even though Angelou is certainly referring to the harhsness that those working in plantations picking up cotton and other products had to endure, particularly in the last hours of the day, when "nature's blessing of grogginess, forgetfulness and the soft lamplight" had faded, hers, I believe, is not a resentful or an outraged tone, at least not in this excerpt. Instead, the tone of the author in this excerpt is solemn, witty, outspoken and persuasive, and it relates to her difficult upbringing and her personal experience as a Civil Rights advocate and activist.
She means that being a black southerner sucked, but it sucked even worse in the hot summer afternoons, which were hot and humid and uncomfortable and by which time everybody had been working hard all day, than in the mornings, when it was more comfortable and people had just gotten out of bed and weren't completely awake and aware of their lousy situation in life.
