This essay suggests that between 1830 and slavery’s end in 1865 the South was in transition. Early in this period, which side of the endogamous color line you were on depended on the rule of blood fraction as modified by the rule of physical appearance and the rule of association.10 Eston Hemings, like his wife Julia Isaacs and her uncle James West, were accepted as White despite slight Black ancestry. But in the decades after 1830, after the North had accepted the notion of invisible Blackness, the idea spread southwards. Courts were at first willing to allow one-drop arguments to be made in court, but such arguments were not conclusive in reaching verdicts. Then after several years, verdicts began to be rendered based on invisible Blackness, although they were overturned. Later, appellate decisions began to uphold such verdicts. Step by step, the one-drop rule spread deeper into the slave states. By 1865, the upper South had apparently become comfortable with a one-drop rule in practice, while still paying lip service to the old blood-fraction laws in theory.