Analyze the following document, a letter written by Benjamin Franklin in 1754 regarding the necessity of colonial unity in the face of French and Native American threats. In your analysis, consider Franklin's arguments for cooperation among the colonies.
Your response should include specific evidence from the document and at least one additional piece of outside evidence related to colonial unity during this period.
Note: The solution includes an example perfect-score answer with a detailed rubric. Your response will not be scored.