What shapes the modern understanding of ancient Mesopotamia? The Worlds of Yesterday explores this question through the life and work of the Assyriologist and historian A. Leo Oppenheim. Drawing on an edition of previously unknown family correspondence written during years of exile and upheaval, Abraham Winitzer places Oppenheim’s famous vision of Mesopotamia as a “dead civilization” within the historical world in which it emerged. Combining intellectual biography, the history of Assyriology, and a remarkable family archive, this two-volume work illuminates the intertwined histories of the twentieth century and the study of the ancient Near East.