Three double-spaced pages is the norm for these, and indeed all the following seminar questions, as described in the online videos. Start by creating a solid thesis statement driven directly by the question below, as covered in the video. Then, by outlining your essay in direct relation to that thesis statement, your writing should flow easily.
What were the influences of history, culture, economics and philosophy on the drafters of the Declaration of Independence? How can you see those influences reflected in that essay and, subsequently, in contemporary American political society?
Pararaph 1: introduction
Pargraph 2: History
Paragrah 3: Culture 
Pargraph 4: Economics
Paragraph 5: Philosophy
Paragraph 6: Reflected in the Declaration of independence
Paragraph 7: reflected in contemporary society 
Paragraph 8: conclude
Sources for essay:

American Governments and Politics Today Esstentials 2017-2018 Edition (Chapter 1: The Declaration of Independence)