Round pin-back button with background of a red stripe at top, a white stripe at center and a blue stripe at the bottom, with the words "Registered 1917 Belleville Illinois" in white letters. The Selective Service Act was passed by Congress on May 18, 1917 and authorized the President of the United States to increase military numbers through mandatory enlistment. All men aged 21 to 30 years of age were required to register for military service for a period of 12 months. Buttons like this seem to commemorate the act of registering with the Selective Service.