Shortly after World War I the Gold Star Mothers Club was formed in the United States to provide support for mothers that lost sons or daughters in the war. The name came from the custom of families of servicemen hanging a banner called a Service Flag in the window of their homes. The Service Flag had a star for each family member in the military. Living servicemen were represented by a blue star, and those who had lost their lives were represented by a gold star. Gold Star Mothers are often politically and socially active. Today, membership in the Gold Star Mothers is available to any American woman who has lost a son or daughter in service to the United States. On the last Sunday in September, Gold Star Mother's Day is observed in the U.S. in their honor. USC Title 36 Sec. 111 The group holds a congressional charter under Title 36 of the United States Code. (taken from Wikipedia)
