When the U.S. entered World War I, Boy Scouts helped raise funds for the war effort and government assistance programs by selling millions of dollars' worth of Liberty Loan Bonds. In 1917 and 1918, Scouts sold 2,350,977 Liberty Loan bonds, totaling $147,876,902; and war savings stamps, to a value of $53,043,698. More than 300 million pieces of government literature were distributed with their help as well. From 1917 to 1919, medals like this were issued to Scouts participating in the program. Some medals had a blue ribbon, and merit bars were added. These can be worthy anywhere from $25-35, on up, depending on ribbon, number of bars, etc. Your May 1919 medal with blue ribbon lists for $35-50.