How did the more than 400 ethnic identities discovered by China’s first modern-era census, conducted in 1953–54, become the 55 national minority groups officially recognized today? Mullaney has discovered the archives of the Yunnan office of the Ethnic Classification Project and has interviewed some of its surviving members, allowing him to reflect on modern state making and identity creation. Yunnan is the southwestern province where almost half the classified minority groups reside. Ironically, the young communist ethnologists dispatched by Beijing in 1954 to “scientifically” classify the groups used a linguistics-based system that, unbeknownst to them, was designed in the early twentieth century by an officer in the “imperialist” British army. In the process, they ended up creating some groups that had never actually existed. But in the decades since, the state has taught the minorities to accept the official categories, and today they are socially real.