Why does poe use chronological events in "the black cat" to organize details of the crime the narrator committed?

Poe uses chronological events in "The Black Cat" to organize details of the crime the narrator committed as:

It allows the reader to see the chain of events that led to the crime as well as the steady progression of the narrator’s insanity.

The short story “The Black Cat” focuses on several themes which at times are seen interacting and intersecting with each other. The theme of happy family life changing towards violence and theme of freedom and confinement are prevailing in the story. Drinking excess of alcohol became a reason for the unnamed narrator to witness a change in his nature. He was a jolly person living with his wife and his pets who were very dear to him. Later, he grew violent and harsh towards them which ended in killing them. Though he wanted to hide everything, his fate turned everything upside down, resulting in his imprisonment. While writing these incidents from prison he declares himself saintly than he was before. The time when he was free and lived with his family he turned to be harsh and a murder but when his life got confined behind the bars of the prison, he became calm and even confessed his wrongdoings.

1. read the following excerpt from franklin d. roosevelt's "fireside chat 19":

on the other side of the picture, we must learn also to know that guerilla warfare against the germans in, let us say serbia or norway, us; that a successful russian offensive against the germans us; and that british successes on land or sea in any part of the world strengthen our hands.

remember always that germany and italy, regardless of any formal declaration of war, consider themselves at war with the united states at this moment just as much as they consider themselves at war with britain or russia. and germany puts all the other republics of the americas into the same category of enemies. the people of our sister republics of this hemisphere can be honored by that fact.  

the true goal we seek is far above and beyond the ugly field of battle. when we resort to force, as now we must, we are determined that this force shall be directed toward ultimate good as well as against immediate evil. we americans are not destroyers — we are builders.

analyze the effectiveness of this excerpt. how does it function within the speech as a whole? how does the structure of the excerpt to convey the speech's purpose and key points? support your argument with evidence from the speech. (10 points)

- "the basic difference between keywords and subjects is that subjects (or "subject headings") have been predetermined, while keywords have not. a keyword is an easy place to start because you can use any word that seems to fit your search; this is called "natural language" searching."