Final answer:
Douglass alludes to the Bible to emphasize the importance of the 4th of July as the birth of national independence and political freedom for the American people.
Step-by-step explanation:
In this paragraph, Douglass alludes to the Bible in order to emphasize the significance and importance of the 4th of July for the American people. He compares the celebration of Independence Day to the Passover, a religious event in the Bible that marked the liberation of the Israelites from slavery in Egypt. By making this allusion, Douglass highlights the idea that the 4th of July represents the birth of national independence and political freedom for the American people, just as the Passover represented liberation for the Israelites.