This kind of question calls for an understanding of the historical period, an imaginative mind, and a good deal of empathy. For instance, in answering the question about George Washington's contributions to the war effort, you may have contended that he was not indispensable. To you, that was a statement of your opinion, interpretation, point of view, etc. Consequently, from now on you will not write an opinion in an essay, you will write a thesis. Every essay should have a thesis, a consistent and logical arrangement which runs throughout your entire essay.
Some questions lend themselves more readily to theses.
Nevertheless, if your essay is going to say anything worth reading, there should be a thesis consistently developed within. Most of you are familiar with the first four notes of Beethoven's Fifth Symphony, but if you listen closely to the Symphony, and the First Movement in particular, you will notice that Beethoven continually returns with those original four notes as if to remind his listeners of the boldness of the introduction. From l776 until eventual victory in 1783, Washington played a decisive role in prosecuting the war, a role which in the long run appears to have been indispensable. Certainly Washington made contributions to the Colonial effort, but in the long run others in the Army could have performed at 1east equally as well as the Father of his Country. B. The Body of your essay is where you use the facts you have learned to prove the validity of your opening position - your thesis.