Hi! Following may be a list for starting your collection in a non-Buddhist context:
Ama, Michihiro. 2011. Immigrants to the Pure Land: The Modernization, Acculturation, and Globalization of Shin Buddhism, 1898-1941. Honolulu, HI: University of Hawai’i Press.
Cadge, Wendy. 2005. Heartwood - The First Generation of Theravada Buddhism in America. Chicago, IL: The University of Chicago Press.
Chen, Carolyn. 2008. Getting Saved in America – Taiwanese Immigration and Religious Experience. Princeton, NJ: Princeton University Press.