After reading SFHG, I thought it might help to contextualize some of the racial and economic undertones that run through the novel. The most obvious theme is that of the Hawaiians vs. Haoles, which has been explained well by Mari below this post. However, there are more subtle tensions prevalent in SFHG, many of which can be explained by the plantation era and how it affected Hawaii both socially and economically (this also has something to do with my final project, so insights are appreciated).
After the overthrow of the monarchy and the subsequent repression of the Hawaiian people and culture, the sugarcane industry moved into Hawaii. The climate was perfect, and the owners of the plantations found that they could easily buy the favors of white officials to expand their operations. Over time, the industry grew so rapidly that the plantations found they could not keep up with demand because of their limited resources and workforces. This led to the importation of workers from all corners of the globe, from Korea and Japan to Portugal and Mexico. These workers immigrated to Hawaii in search of money and a new life; most were poor and jobless, with little or no assets and education. The workers stayed in shantytowns built around the plantations, called "camps"; basically run-down public housing with poor facilities and worse living conditions. The influx of workers, however, gave the sugar industry a huge lift and provided Hawaii with a semi-stable economy with which to bring income in.
You can imagine the variety of cultures and races that were thrown together in the early plantation era; Filipinos working alongside Spanish and Brazilians, cutting down the cane beside Chinese and Vietnamese. When people refer to Hawaii as a cultural melting pot, they are speaking directly to the vastness of cultural differences that existed because of the plantation life. As you can imagine, there were problems with communication between the workers themselves, as well as with the white owners. Additionally, the different social norms that each race brought with them meant tension between cultures as they were suddenly exposed to people with much different ideas about food, labor, and family dynamics.
From this tension came a new kind of culture, a conglomeration that eventually became the overall "Hawaiian" culture we see today. In present Hawaii, we see many different influences from different races: taking your shoes off before entering a house, from the Japanese; celebrating a child's first birthday, from the Hawaiians; popping fireworks on the New Year, from the Chinese and a plethora of other cultural norms adopted from each plantation-era race into Hawaiian society today. The predominant foods of Hawaii are heavily influences by the Phillipines, Asia, and ancient Hawaii, and the style of English most widely spoken around the islands, called "pidgin", comes from a sort of creole developed by the early workers, giving them a means of communication that everyone could understand.
How does this affect SFHG? Obviously the themes of Hawaiian vs. White are relevant in that the Hawaiians feel animosity toward the people who have taken their land and repressed the traditions and culture of their people. However, there are other places where different themes are taken into account. Sam's mother always corrects him when he speaks in pidgin, a dialect that she feels is unintelligent and demeaning. This attitude is shared among many people in Hawaii, although pidgin is in fact a diverse language capable of bringing people who might not be able to communicate regularly together. There are a few other things that I want to put in my paper so I'll save them for that, but the scope of the sugar cane industry and its effects on Hawaii are significant and play a large role in the novel, as well as Hawaiian society today.