Henry Morgenthau Jr. was the United States Secretary of the Treasury during most of the administration of Franklin D. Roosevelt. He played a major role in designing and financing the New Deal. After 1937, while still in charge of the Treasury, he played the central role in financing United States participation in World War II. He also played an increasingly major role in shaping foreign policy, especially with respect to Lend-Lease, support for China, helping Jewish refugees, and proposing measures to deindustrialize and ethnically cleanse a massive portion of the German population.

The United States secretary of the treasury is the head of the United States Department of the Treasury, and is the chief financial officer of the federal government of the United States. The secretary of the treasury serves as the principal advisor to the president of the United States on all matters pertaining to economic and fiscal policy. The secretary is, by custom, a member of the president's cabinet and, by law, a member of the National Security Council.