Diehl worked with Castle behind the scenes to move legislation forward despite the Treasury's opposition to the program. However, the Treasury suggested to Castle that the department should conduct a study to determine the feasibility of the program. With Diehl's advice, Castle accepted the Treasury's offer, and the agreement was codified in the United States Commemorative Coin Act of 1996. The act also authorized the secretary to proceed with the 50 States Quarters Program without further congressional action if the results of the feasibility study were favorable.