Answer:
Ramona by Helen Hunt Jackson
Step-by-step explanation:
The book entitled "Ramona" depicted the life of living in a Mexican rancho. It also showed how the Native Americans were mistreated. However, this was not the reason why the Americans became interested and excited about it. They were after the love story of Ramona (including the happenings in her life) and the made-up Mexican-Spanish culture in southern California.
This book paved way to tourism. Many people were interested to go to the country through the Santa Fe Railroad. It also increased the amount of trade in the regions that were mentioned in the book. As people flock towards southern California, the population grew rapidly.
So, this explains the answer.