Sweetheart jewelry was a token of affection from a service member originally given to their sweetheart. This tradition started in WWI, but became increasingly more popular during World War II era (1939-1945), as cloth was rationed as part of the war effort. As a result, clothing was unadorned and simple.
Wearing a sweetheart brooch, bracelet or necklace not only served as a connection to a loved one who was fighting overseas but gave the wearer a sense of style. Sweetheart jewelry expanded to all relations, including wife, girlfriend, mothers, and sisters.