Inherit the Wind is not a literal historical account of the Scopes "Monkey Trial," nor did its authors claim it was. Some of the actual events have been omitted, other, fictional, incidents and scenes have been added, and the names have of course been changed, though the fictional names are similar to the real ones. (The triple-named William Jennings Bryan becomes Matthew Harrison Brady, H.L. Mencken becomes E.K. Hornbeck, and so on.)

The actual differences between the Scopes trial and its fictionalized version in the play can be easily looked up, but the real question is this: why did Lawrence and Lee make the specific changes they did? What did they wish to emphasize in the drama of ideas they were creating?

We can choose one particular aspect of these differences and examine it as a key to the authors' approach. In the play, Bertram Cates, the Scopes character, is engaged to the daughter of a clergyman. This emphasizes the conflict between religion and freedom of thought at the heart of the play. In reality, Bryan did not collapse and die at the trial, as Brady does in the play. This is a telescoping of the historical record, but its purpose is to allow Drummond and Hornbeck to reflect on what Brady has represented to them. Hornbeck acts as a kind of chorus throughout the play, speaking in verse-like lines. You might ask what his final comment means in relation to the play's overall themes: that he must "go and type out the story of an atheist"—Drummond—"who believes in God."

I would say that the trial being set in Hillsboro is extremely important.  Its rural and traditional setting becomes the perfect backdrop to fully grasp the fundamental conflict at the time between scientific explanations and religious interpretation.  The time period being a moment where scientific explanations were supplanting the accepted traditionalist approaches helps to heighten the tension that is felt between Bert Cates and the rest of the town, especially Reverend Brown.  I think that the escalation of tension in the courtroom throughout the proceedings helps to bring the drama between this collision between both of these polarities.  The historical element present might not be well suited to be treated as pure historic fact, as much as exploration of the tension between both philosophical premises in a moment in American History, which certainly has had and does have some challenges at moments with the reconciliation between science and religion.

The setting in many ways is vital to the story as it was chosen by the real town that they would be the place to have this debate take place in the form of a trial.  It provides a great deal of drama for the movie as well given that it takes place in the South, always seen as a hotbed for revivalist and evangelical religious feeling, some of the main opposing forces to the idea of teaching evolution in schools at the time.

The setting also provides another element of conflict as it pits the Northern lawyer against the southern one, and two mindsets of the two different regions against each other as well.