On March 15, 1947, Clay succeeded Eisenhower as military governor (or "high commissioner" ) of occupied Germany—the head of the OMGUS, the "Office of Military Government, United States". Clay's responsibilities covered a wide spectrum of social issues related to Germany's recovery from the war in addition to strictly military issues. He commissioned Lewis H. Brown to research and write "A Report on Germany," which served as a detailed recommendation for the reconstruction of post-war Germany, and served as a basis for the Marshall Plan. Clay promoted democratic federalism in Germany and resisted US politicians who sought to undo a conservative constitution adopted in Bavaria. He also closed the borders of the American Zone in 1947 to stem the tide of Jewish refugees who were generating tension with the local populations.
The headquarters of the American military government was the former IG Farben Building in Frankfurt am Main.
The Office of Military Government, United States (OMGUS; Amt der Militärregierung für Deutschland (U.S.)) was the United States military-established government created shortly after the end of hostilities in occupied Germany in World War II. Under General Lucius D. Clay, it administered the area of Germany and sector of Berlin controlled by the United States Army. The Allied Control Council comprised military authorities from the United States, the United Kingdom, the Soviet Union and France. Though created on January 1, 1946, OMGUS previously reported to the U.S. Group Control Council, Germany (USGCC), which existed from May 8, 1945 until October 1, 1945. OMGUS was eliminated on December 5, 1949, and the U.S. High Commissioner for Germany assumed control of its functions.
As a manufacturing centre, Munich was heavily bombed during World War II and was occupied by U.S. troops, becoming a major part of the American Zone of Allied-occupied Germany (1945–47) and then of "Bizonia".