Final answer:
Henry and Sheldon are likely surprised by the social dynamics in Walla Walla, which might relate to the community's friendliness or racial demographics. Their surprise can be understood against the backdrop of historical race relations in the US.
Step-by-step explanation:
The question posed by Henry and Sheldon about their surprise in Walla Walla likely relates to the social and cultural conditions they encounter. Considering the provided context, it's apparent that they might be surprised by either the friendliness of the community, the racial makeup, or both. The historical examples given highlight the complexities of race in American society, from the forced segregations of Asian railroad workers to the perceptions of students of color in educational settings. These narratives reveal that race can significantly shape people's experiences and perceptions of a place and its community.
The question does not directly correlate with the provided context, but it allows us to understand that the assumptions Henry and Sheldon had about Walla Walla could be rooted in their prior understandings or misunderstandings of race and community interactions, influenced by their backgrounds and the historical context of race relations in the United States.