By the early 1930s the British Museum and Penn Museum were facing a world radically changed from the early 1920s. In particular, the Penn Museum had been hard hit by the Great Depression. On the advice of its Board of Managers, Museum Director Horace Jayne, who had succeeded George Byron Gordon, wrote to Woolley on May 9, 1933, to suggest he close the excavations. Jayne noted that the Carnegie Foundation had provided $25,000 in 1931 for publication, so publication was imperative. Additional excavations would only increase the backlog of data. He also suggested that “the possibilities of the site might be nearing exhaustion,” and that something should be left for future archaeologists. Jayne also observed that Woolley might equally be nearing exhaustion after ten years of strenuous fieldwork.
Although Woolley was worried by threats to change Iraq’s 1924 Antiquities Law, he nevertheless argued for one more season. His main objective was to uncover additional graves from the poorly documented Jemdet Nasr period (ca. 3100–2900 BCE), which he felt was necessary for publication. To reach this early phase he dug Pit X. At the surface of the mound, Pit X measured 1000 m2. Under the supervision of Woolley’s wife, Katharine, the workmen removed 13,160 m3 of soil in less than two months—an extraordinary effort that resulted in an 18 meter deep pit that measured 440 m2 at its base.
On February 25, 1934, Woolley ended his twelfth season of excavations. No excavations have taken place at Ur since then.