Final answer:
Franklin's cartoon was effective due to its simple yet powerful visual metaphor which communicated the necessity of colonial unity. It appealed to the colonists with its clear message, and regardless of initial beliefs, its stark warning was persuasive and provoked the necessary thought on the urgency of collective action.
Step-by-step explanation:
Franklin's cartoon was highly effective as a form of propaganda due to its simplicity and directness. The main argument of the cartoon, which is often a dissection of a political or social issue, is usually conveyed through visual metaphor and allegory. In the case of Franklin's cartoon, the primary analogy was that of a divided snake labeled with the names of the colonies, which conveyed the message that if the colonies did not unite, they would perish independently.
The clarity of the cartoon's analogy made it easy for viewers of that time to understand the message, while its ability to persuade can be seen in the rallying of the colonies for collective action. The cartoon's intended audience was the colonists who, regardless of their stance before seeing the cartoon, could understand the dire consequences of continued disunity.
Different audiences would likely react based on their prior beliefs about unity and the colonial cause, but the cartoon's stark warning carries persuasive power regardless. By presenting a clear visual metaphor and an urgent message, the cartoon was able to capture attention and provoke thought on the critical issue of colonial unity. In terms of the effectiveness of visual communication, this suggests that political cartoons are a powerful medium for conveying complex ideas in a straightforward manner.