Answer: The method that Jackson used for creating an effective conclusion was that of a quotation.
Step-by-step explanation: The conclusion of a speech dispenses the final and the most important message of the speech. It has been found that most people who attend a speech remember the concluding part the best.
Using a quote to conclude a speech helps the speaker place due emphasis on his message by making the listeners realize that the speaker's message resembles with other famous and reliable ideologies. This helps listeners trust the speaker to a greater degree.