What is the main conflict in Dragonwings by Laurence Yep?

In this novel, Moon Shadow comes to America to be with his father, Windrider, from their home in the Middle Kingdom. As Moon Shadow and his father struggle to survive in a hostile country, they somehow find time to focus on their dreams. Windrider has read about the flying machine the Wright brothers built and believes he can build a better one and fly. Moon Shadow struggles alongside his father as they both build their dream and work to survive both natural and man-made disasters. Dragonwings is a novel of the Asian community of the early 1900s and the spirit that kept them from giving up their dreams.