When Angelou wrote I Know Why the Caged Bird Sings at the end of the 1960s, one of the necessary and accepted features of literature, according to critic Pierre A. Walker, was thematic unity. One of Angelou's goals was to create a book that satisfied this criterion, in order to achieve her political purposes, which were to demonstrate how to resist racism in America. The structure of the text, which resembles a series of short stories, is not chronological but rather thematic. Walker, in his 1993 article about Caged Bird, "Racial Protest, Identity, Words, and Form", focuses on the book's structure, and describes how it supports her presentation of racism. According to Walker, critics had neglected analyzing its structure, choosing to focus instead on its themes, which he feels neglects the political nature of the book. He states, "One serves Angelou and Caged Bird better by emphasizing how form and political content work together". Angelou structures her book so that it presents a series of lessons about how to resist racism and oppression. The progression Maya goes through thematically unifies the book, something that "stands in contrast to the otherwise episodic quality of the narrative". The way in which Angelou constructs, arranges, and organizes her vignettes often undermined the chronology of her childhood by "juxtaposing the events of one chapter with the events of preceding and following ones so that they too comment on each other".
For example, the incident with the "powhitetrash" girls takes place in chapter 5, when Maya was ten years old, well before Angelou's recounting of her rape in chapter 12, which occurred when Maya was 8. Walker explains that Angelou's purpose in placing the vignettes in this way is that it followed her thematic structure. Angelou's editor, Robert Loomis, agrees, stating that Angelou could rewrite any of her books by changing the order of her facts to make a different impact on the reader. Hagen sees Angelou's structure somewhat differently, focusing on Maya's journey "to establish a worthwhile self-concept", and states that she structures the book into three parts: arrival, sojourn, and departure, which occur both geographically and psychologically. However, Hagen notes that instead of beginning Caged Bird chronologically, with Maya and Bailey's arrival in Stamps, Angelou begins the book much later chronologically by recounting an embarrassing experience at church, an incident that demonstrates Maya's diminished sense of self, insecurity, and lack of status. Hagen explains that Angelou's purpose is to demonstrate Maya's journey from insecurity to her feelings of worth gained by becoming a mother at the end of the book.