The first person narrative is the point of view of the person who is telling the story. The character might be speaking about himself and shares events that he experienced and also can be recognized by the use of "I" or "us" in the text. Since it's mentioned above that the character shares his perspective, the text is narrated in the first person.
The answer to your question would be, “to show that despite its differences, America is still a country that unites in times of strife.” Hope this helps!:)
