In 1848, American missionary Samuel Wells Williams wrote The Middle Kingdom, a 1,200-page behemoth meant to introduce American readers to Chinese history and culture, with the hope that it would “increase an interest among Christians in the welfare of [the Chinese], and show how well worthy they are of all the evangelizing efforts that could be put forth…” Williams, a veteran missionary based in Canton, went on to serve in China for the next thirty years as a Protestant missionary and American diplomat. After returning permanently to the US in the late 1870s, Williams emerged as a proponent of the rights of Chinese migrants in the United States, and also began to revise his earlier masterwork. In this paper, I compare the 1848 edition of The Middle Kingdom to the revised 1883 edition, and argue that Williams’ changes were profoundly influenced by his advocacy for Chinese migrants, and were meant to advance a message that ran counter to the dominant anti-Chinese immigration and anti-Chinese rights political and social narratives that prevailed in the early 1880s.