In Chapter 10, Angelou utilizes verbal irony in her initial portrayal of St. Louis:
The Negro section of St. Louis in the mid-thirties had all the finesse of a gold-rush town. Prohibition, gambling, and their related vocations were so obviously practiced that it was hard for me to believe that they were against the law.
Angelou states that St. Louis had "all the finesse of a gold-rush town" in the mid-1930s, by which she means to imply the opposite: neither St. Louis or the gold-rush towns have any finesse, in her mind. The American gold-rush towns of the late 19th and early 20th centuries were often hastily-constructed affairs, built quickly to accommodate large numbers of (mostly) men moving west to search for gold. These towns were often rife with criminal activity, lacking law enforcement infrastructure—or even, at times, laws.
Through verbal irony, Angelou reveals that St. Louis has similar issues with lawlessness. Indeed, many of the perpetrators of said lawlessness are members of her own family: it is heavily implied by Angelou that Mr. Freeman's death was not accidental, but caused by one or more of her uncles after the trial. St. Louis's instability therefore thematically reflects on the general instability of Angelou's family situation.