On May 11, 1941, President Roosevelt signed the Executive Order 8734 which created the Office of Price Administration and Civilian Supply (OPACS). On August 28, 1941, an Executive Order 8875 transformed OPACS into the Office of Price Administration (OPA). After the US entered WWII in December 1941, OPA was tasked with rationing. The Emergency Price Control Act passed on January 30, 1942, legitimized the OPA as a separate federal agency. It merged OPA with two other agencies: Consumer Protection Division and Price Stabilization Division of the Advisory Commission to the Council of National Defense. The council was referred to as the National Defense Advisory Commission (NDAC), and was created on May 29, 1940. NDAC emphasized voluntary and advisory methods in keeping prices low. Leon Henderson, the NDAC commissioner for price stabilization, became the head of OPACS and of OPA in 1941–1942. He oversaw a mandatory and vigorous price regulation that started in May 1942 after OPA introduced the General Maximum Price Regulation (GMPR). It was heavily criticized by the American Business community. In response, OPA mobilized the public on behalf of the new guidelines and said that it reduced the options for those who were seeking higher rents or prices. OPA had its own Enforcement Division, which documented the rising tide of violations: quarter million in 1943 and more than 300,000 during the next year.