Let us answer it with W.S.S. : war savings stamps issued by the United States Government.

Bibliographic Details
Corporate Author:	United States. War Loan Organization. Savings Division
Format:	Photo
Language:	English
Subjects:	World War, 1914-1918 > Finance > United States > Posters. Savings stamps > United States > History > 20th century > Posters. War posters, American. Posters.

Cushing: Ragan Military (Does not check out)