Between 1848 and the early twentieth century, the Wuyi (五邑, Wǔyì, the "five counties") region of Guangdong — Taishan (台山, Táishān), Kaiping (开平, Kāipíng), Enping (恩平, Ēnpíng), Xinhui (新会, Xīnhuì), and Heshan (鹤山, Hèshān) — sent an outsized share of the Chinese who crossed the Pacific to the United States. Whole villages emptied their young…