(Thesis statement) How did the Civil War start?

What role did Abraham Lincoln play in civil war?
why does the civil war have so much impact on US history
(The paper should show the impact of the civil war in all the positive and negative affects Abraham Lincoln did to make the Civil War such a great part of history)
(Come up with a thesis statement for the conclusion) one sentence that sums up your argument based on the facts/evidence from the research.