In 1904, Einar Holboell, a Danish postal clerk developed the idea of a seal on envelopes during Christmas to raise money for tuberculosis. The plan was approved by the Postmaster and the King of Denmark, and the first seal bore the likeness of the Queen and the words "Merry Christmas". Over 4 million were sold in the first year.
It grew to a national program in 1908 by the National Association for the Study and Prevention of Tuberculosis (NASPT) and the American National Red Cross. The seals were sold at post offices, initially in Delaware at 1 cent each. Net proceeds from the sales would be divided equally between the two organizations. By 1920, the Red Cross withdrew from the arrangement and sales were conducted exclusively by the NASPT, then known as the National Tuberculosis Association (NTA). NTA became the American Lung Association in 1973.
Today the Christmas Seals benefit the American Lung Association and other lung related issues. Tuberculosis was declining, but recently has been on the rise. TB is still the most common major infectious disease in the world.
See also
Easter Seals - a similar program aimed at disabilities.