Compare and Contrast the Reasons Why the North and South Fought the Civil War

Examples
Suppose you are taking a course on 19th-century America, and the instructor hands out the following essay assignment: Compare and contrast the reasons why the North and South fought the Civil War. You turn on the computer and type out the following:
The North and South fought the Civil War for many reasons, some of which were the same and some different.
This weak thesis restates the question without providing any additional information. You will expand on this new information in the body of the essay, but it is important that the reader know where you are heading. A reader of this weak thesis might think, "What reasons? How are they the same? How are they different?" Ask yourself these same questions and begin to compare Northern and Southern attitudes (perhaps you first think, "The South believed slavery was right, and the North thought slavery was wrong"). Now, push your comparison toward an interpretation—why did one side think slavery was right and the other side think it was wrong? You look again at the evidence, and you decide that you are going to argue that the North believed slavery was immoral while the South believed it upheld the Southern way of life. You write:
While both sides fought the Civil War over the issue of slavery, the North fought for moral reasons while the South fought to preserve its own institutions.
Now you have a working thesis! Included in this working thesis is a reason for the war and some idea of how the two sides disagreed over this reason. As you write the essay, you will probably begin to characterize these differences more precisely, and your working thesis may start to seem too vague. Maybe you decide that both sides fought for moral reasons, and that they just focused on different moral issues. You end up revising the working thesis into a final thesis that really captures the argument in your paper:
While both Northerners and Southerners believed they fought against tyranny and oppression, Northerners focused on the oppression of slaves while Southerners defended their own right to self-government.
Compare this to the original weak thesis. This final thesis presents a way of interpreting evidence that illuminates the significance of the question. Keep in mind that this is one of many possible interpretations of the Civil War—it is not the one and only right answer to the question. There isn't one right answer; there are only strong and weak thesis statements and strong and weak uses of evidence.
Let's look at another example. Suppose your literature professor hands out the following assignment in a class on the American novel: Write an analysis of some aspect of Mark Twain's novel Huckleberry Finn. "This will be easy," you think. "I loved Huckleberry Finn!" You grab a pad of paper and write:
Mark Twain's Huckleberry Finn is a great American novel.
Why is this thesis weak? Think about what the reader would expect from the essay that follows: you will most likely provide a general, appreciative summary of Twain's novel. The question did not ask you to summarize; it asked you to analyze. Your professor is probably not interested in your opinion of the novel; instead, she wants you to think about whyit's such a great novel—what do Huck's adventures tell us about life, about America, about coming of age, about race relations, etc.? First, the question asks you to pick an aspect of the novel that you think is important to its structure or meaning—for example, the role of storytelling, the contrasting scenes between the shore and the river, or the relationships between adults and children. Now you write:
In Huckleberry Finn, Mark Twain develops a contrast between life on the river and life on the shore.
Here's a working thesis with potential: you have highlighted an important aspect of the novel for investigation; however, it's still not clear what your analysis will reveal. Your reader is intrigued, but is still thinking, "So what? What's the point of this contrast? What does it signify?" Perhaps you are not sure yet, either. That's fine—begin to work on comparing scenes from the book and see what you discover. Free write, make lists, jot down Huck's actions and reactions. Eventually you will be able to clarify for yourself, and then for the reader, why this contrast matters. After examining the evidence and considering your own insights, you write:
Through its contrasting river and shore scenes, Twain's Huckleberry Finn suggests that to find the true expression of American democratic ideals, one must leave "civilized" society and go back to nature.
This final thesis statement presents an interpretation of a literary work based on an analysis of its content. Of course, for the essay itself to be successful, you must now present evidence from the novel that will convince the reader of your interpretation.