Alaudin Ullah has spent more than 20 years collecting untold or overlooked stories of the earliest South Asian immigrants to America, their Black and Hispanic wives, and their descendants, particularly in New York. It’s a research project, but also a personal one: The project has been a way for him to understand his own story, too—and his father’s. Ullah’s dad, a Bengali sailor named Habib Ullah, moved to America in 1924. He didn’t speak much English and couldn’t read or write. But when his ship docked in Boston, Habib stayed…