How does Puccini distinguish the American characters musically in Madama Butterfly?

To distinguish the American characters in Madama Butterfly, Giacomo Puccini employed a specific musical approach characterized by a bluff, forthright manner of expression. Furthermore, he occasionally incorporated melodic fragments of "The Star-Spangled Banner" into the score to signify their national identity.1

This stylistic choice served as a musical contrast to the elements of Japanese music that Puccini researched and integrated into the opera to provide local color and realism.1