H GAYLORD HITCHCOCK JR

At the end of the fourth century, as the power of Rome faded and Constantinople became the seat of empire, a new capital city was rising in the West. Here, in Ravenna on the coast of Italy, Arian Goths and Catholic Romans competed to produce an unrivaled concentration of buildings and astonishing mosaics. For three centuries, the city attracted scholars, lawyers, craftsmen, and religious luminaries, becoming a true cultural and political capital.

In 2006, an oddball group of bankers, traders and brokers from some of the world's largest financial institutions made a startling realization: Libor - the London interbank offered rate, which determines the interest rates on trillions in loans worldwide - was set daily by a small group of easily manipulated functionaries, and that they could reap huge profits by nudging it to suit their trading portfolios.

Over the last decade, a single innovation has massively fueled digital black markets: cryptocurrency. Crime lords inhabiting lawless corners of the internet have operated more freely—whether in drug dealing, money laundering, or human trafficking—than their analog counterparts could have ever dreamed of. By transacting not in dollars or pounds but in currencies with anonymous ledgers, overseen by no government, beholden to no bankers, these black marketeers have sought to rob law enforcement of their chief method of cracking down on illicit finance: following the money.

They say that history is written by the victors. But not in the case of the most famous dissenter on the Supreme Court. Almost a century after his death, John Marshall Harlan’s words helped end segregation and gave us our civil rights and our modern economic freedom. But his legacy would not have been possible without the courage of Robert Harlan, a slave who John’s father raised like a son in the same household.