The Richard B. Witschonke Collection of nearly 4,000 coins, bequeathed to the American Numismatic Society in 2015, are now published fully for the first time. These coins provide the historical and numismatic prologue to the study of Roman provincial coinage. Most of the specimens are of great historical and numismatic value, as explained in the historical introductions preceding each of the 38 sections of this catalogue. This collection offers a unique overview of the diverse ways in which the monetary systems of the Mediterranean basin responded to the Roman conquest in the second and early first centuries BCE and to the related necessity of interconnectivity.