Using new archival research, this book shows how Union Theological Seminary exported progressive Christianity to Communist China. Founded in 1836, the New York seminary disseminated its version of Christianity to China through its alumni. From 1911 to 1949, 196 Union alumni went to China. Thirty-nine of these former students were Chinese nationals. Many of these Chinese students—such as Y. T. Wu (Wu Yaozong), K. H. Ting (Ding Guangxun), John Sung (Song Shangjie), and Timothy Tingfang Lew (Liu Tingfang)—became key leaders in the Sino-Foreign Protestant Establishment and the Three-Self Patriotic Movement. The school became a dense hub of influential Chinese and American Christians. Union's role in liberalizing and indigenizing Christianity in twentieth-century China has been largely unnoticed, until now.