"The federal duck stamp was created through a wetlands conservation program. President Herbert Hoover signed the Migratory Bird Conservation Act in 1929 to authorize the acquisition and preservation of wetlands as waterfowl habitat.
The law, however, did not provide a permanent source of money to buy and preserve the wetlands. On March 16, 1934, Congress passed, and President Roosevelt signed, the Migratory Bird Hunting Stamp Act. Popularly known as the Duck Stamp Act, the bill's whole purpose was to generate revenue designated for only one use: acquiring wetlands for what is now known as the National Refuge System.
It has been proven that sales of duck stamps increase when the public has been informed of how the revenue generated through stamp sales is used."